Details of a Researcher - Watanabe, Koota

Papers - Watanabe, Koota

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Can Postoperative Distal Adding-On be Predicted in Lenke Type 1B and 1C Curves with Intraoperative Radiographs?

Fujii T., Kawabata S., Suzuki S., Tsuji O., Nori S., Okada E., Nagoshi N., Yagi M., Michikawa T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 47 ( 6 ) E215 - E221 2022.03

ISSN 03622436

Study Design.A retrospective study of consecutive collected data.Objective.To investigate risk factors for postoperative distal adding-on (DA) in Lenke Type 1B and 1C curves using intraoperative radiographs.Summary of Background Data.In adolescent idiopathic scoliosis (AIS), DA radiographic complication can negatively affect postoperative clinical results. However, few studies have focused on assessing risk factors for DA using intraoperative radiographs.Methods.We retrospectively evaluated 69 AIS patients with Lenke Type 1B or 1C curves who underwent posterior selective thoracic fusion. We divided patients into DA and non-DA groups based on radiograph data at 2-year follow-up using Wang et al (Spine 2011) definition of DA. We compared coronal radiographic parameters, including relative positions of end vertebra (EV), stable vertebra (SV), neutral vertebra (NV), and last touching vertebra (LTV) to lowest instrumented vertebra (LIV), and intraoperative radiographic parameters, between the two groups.Results.DA was present in 13 patients (18.8%) at 2-year follow-up. The mean LIV-EV, LIV-NV, LIV-SV, and LIV-LTV relative positions were significantly smaller in the DA group than in the non-DA group. Multivariate analysis showed that LIV-LTV was significantly associated with DA (DA: -0.2 ± 0.7, non-DA: 0.6 ± 0.7). Intraoperative radiographs showed that the mean angulation of the first disc below the LIV after final adjustment was significantly larger in the DA group (2.3° ± 1.1°) than in the non-DA group (0.9° ± 0.7°). Patients whose angulation of the first disc below the LIV was more than 3° were significantly associated with DA.Conclusion.The LIV selected at more cranial to the LTV may be a risk factor for postoperative DA in Lenke Type 1B and 1C curves. Moreover, it was suggested that LIV extension might be considered when the first disc's angulation below the LIV is >3° in intraoperative radiographs.Level of Evidence: 3.

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Influence of Intervertebral Level of Stenosis on Neurological Recovery and Reduction of Neck Pain after Posterior Decompression Surgery for Cervical Spondylotic Myelopathy: A Retrospective Multicenter Study with Propensity Scoring

Nori S., Nagoshi N., Aoyama R., Ishihara S., Fujiyoshi K., Shiono Y., Kitamura K., Ishikawa M., Suzuki S., Takahashi Y., Tsuji O., Yagi M., Nakamura M., Matsumoto M., Watanabe K., Ishii K., Yamane J.

Spine (Spine) 47 ( 6 ) 476 - 483 2022.03

ISSN 03622436

Study Design.Retrospective multicenter study.Objective.To identify the impact of the intervertebral level of stenosis on surgical outcomes of posterior decompression for cervical spondylotic myelopathy (CSM).Summary of Background Data.As the upper affected cervical levels in elderly patients result from degenerative changes in the lower cervical levels with aging, it is usually difficult to determine the influence of the upper affected cervical levels on surgical outcomes after posterior decompression for CSM in older age.Methods.This study involved 636 patients with CSM who underwent posterior decompression. According to the most stenotic intervertebral level, patients were divided into upper (n = 343, the most stenotic intervertebral level was C2/3, C3/4, or C4/5) and lower (n = 293, the most stenotic intervertebral level was C5/6, C6/7, or C7/T1) cervical stenosis groups. Propensity score matching of the baseline factors (characteristics, comorbidities, and neurological function) was performed to compare surgical outcomes, the Japanese Orthopaedic Association (JOA) scores, and visual analog scale (VAS) for neck pain between the upper (n = 135) and lower (n = 135) cervical stenosis groups.Results.Before propensity score matching, age at surgery was older and pre- and postoperative JOA scores were lower in the upper cervical stenosis group (P < 0.001, P < 0.001, and P < 0.001, respectively). Following matching, baseline factors were comparable between the groups. Postoperative JOA scores, preoperative-to-postoperative changes in the JOA scores, and the JOA score recovery rate were not significantly different between the groups (P = 0.866, P = 0.825, and P = 0.753, respectively). No differences existed in postoperative VAS for neck pain and preoperative-to-postoperative changes in VAS for neck pain between the groups (P = 0.092 and P = 0.242, respectively).Conclusion.The intervertebral level of stenosis did not affect surgical outcomes after posterior decompression for CSM.Level of Evidence: 3.

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Clinical outcomes and a therapeutic indication of intramedullary spinal cord astrocytoma

Nagoshi N., Tsuji O., Suzuki S., Nori S., Yagi M., Okada E., Okita H., Fujita N., Ishii K., Matsumoto M., Nakamura M., Watanabe K.

Spinal Cord (Spinal Cord) 60 ( 3 ) 216 - 222 2022.03

ISSN 13624393

Study design: Retrospective cohort study. Objectives: Although intramedullary astrocytoma is associated with a high mortality rate, the optimal treatment has not reached a consensus. This study aimed at evaluating neurologic function and overall survival rate (OSR) in the treatment of this tumor. Setting: The single institution in Japan. Methods: This study enrolled 67 subjects who underwent surgical treatment for intramedullary astrocytoma. Demographic, imaging, and surgical information were collected from each participant. Tumors were histologically categorized using the World Health Organization classification, and subjects were divided into low-grade (I and II; n = 40) and high-grade (III and IV; n = 27) groups. Neurologic status was evaluated using the modified McCormick scale (MMS). OSR was assessed using Kaplan–Meier methods. Results: The OSR decreased when the pathological grade increased (p < 0.01). Regarding the therapeutic efficacy for low-grade astrocytomas, subjects who underwent gross total resection (GTR) showed a higher OSR than those who did not (p = 0.02). GTR prevented worsening of MMS score, while non-GTR increased the MMS score (p < 0.01). In the high-grade group, 19 and 10 underwent radiation therapy and chemotherapy, respectively. However, both treatments did not improve OSR. Cordotomy was performed for subjects whose lesional area was at the thoracic level, but the OSR did not significantly increase. Conclusions: The most beneficial therapeutic strategy for low-grade astrocytomas was GTR, whereas that for the high-grade tumors was unclear. Further studies with a larger sample size are warranted to validate the effective treatment for malignant astrocytomas.

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Spontaneous Osseous Fusion after Remodeling Therapy for Chronic Atlantoaxial Rotatory Fixation and Recovery Mechanism of Rotatory Range of Motion of the Cervical Spine

Kitamura K., Ishii K., Nagoshi N., Chiba K., Matsumoto M., Nakamura M., Watanabe K.

Journal of Clinical Medicine (Journal of Clinical Medicine) 11 ( 6 ) 2022.03

We aimed to investigate the risk factors of spontaneous osseous fusion (SOF) of the at-lantoaxial joint after closed reduction under general anesthesia followed by halo fixation (remodeling therapy) for chronic atlantoaxial rotatory fixation, and to elucidate the recovery mechanism of the rotatory range of motion (ROM) after halo removal. Twelve patients who underwent remodeling therapy were retrospectively reviewed. Five patients with SOF were categorized as the fusion group and seven patients without SOF as the non-fusion group. Three dimensional CT was used to detect direct osseous contact (DOC) of facet joints before and during halo fixation, while dynamic CT at neutral and maximally rotated head positions was performed to measure rotatory ROM after halo removal. The duration from onset to initial visit was significantly longer (3.2 vs. 5.7 months, p = 0.04), incidence of DOC during halo fixation was higher (0/7 [0%] vs. 4/5 [80%], p = 0.004), and segmental rotatory ROM of Occiput/C1 (Oc/C1) at final follow-up was larger (9.8 vs. 20.1 degrees, p = 0.003) in the fusion group. Long duration from the onset to the initial visit might induce irreversible damage to the articular surface of the affected facet, which was confirmed as DOC during halo fixation and resulted in SOF. Long duration from the onset to the initial visit and DOC during halo fixation could be used to suggest the risk for SOF. Nonetheless, rotatory ROM of Oc/C1 increased to compensate for SOF.

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Surgical Predictors for Prevention of Postoperative Shoulder Imbalance in Lenke Type 2A Adolescent Idiopathic Scoliosis

Sato T., Yonezawa I., Matsumoto H., Otomo N., Suzuki T., Manabe N., Demura S., Watanabe K., Saito T., Nohara A., Kurakawa T., Shimizu T., Uno K., Matsumoto M., Kawakami N.

Spine (Spine) 47 ( 4 ) E132 - E141 2022.02

ISSN 03622436

Study Design. Multicenter, retrospective cohort study. Objective. The aim of this study was to investigate the occurrence and surgical predictors of postoperative shoulder imbalance (PSI) in Lenke type 2A adolescent idiopathic scoliosis (AIS). Summary of Background Data. Although several studies have investigated the factors influencing PSI in Lenke type 2 curves, no studies have analyzed PSI-related factors considering upper instrumented vertebra (UIV) and lumbar modifier type simultaneously. Methods. Patients with Lenke Type 2A AIS treated by spinal fusion were retrospectively identified and their data were extracted from six spine centers in Japan. Inclusion criteria were age between 10 and 20years at surgery, UIV=T2, major curve 408 to 908, and follow-up for 24 to 30months after surgery. We analyzed patient characteristics, surgical characteristics, and preoperative and immediate-postoperative radiographic parameters. We defined patients with lower instrumented vertebra (LIV) equal or proximal to the last touching vertebra (LTV) as selective thoracic fusion (STF-LTV) and patients with LIV distal to the LTV as non-STF-LTV. t Tests, Mann-Whitney U test, χ2 tests, Fisher exact tests, and multivariate logistic regression were used for statistical analyses. Results. Among the 99 consecutive patients with a mean follow-up of 25.6months, PSI was seen in 27 (27.3%) patients immediately after and in 17 (17.2%) patients at 24 to 30months. The univariate analysis revealed that the significant risk factors of PSI were preoperative radiographical shoulder height, non-STF-LTV, and high main thoracic curve (MTC) correction (immediate-postoperative MTC correction rate: ≥70%), with PSI incidence of 40.0%. The multivariate logistic regression analysis indicated that interaction term of non-STF-LTV and high MTC correction was an independent risk factor for PSI (non-STF-LTV and high MTC correction, odds ratio: 5.167, 95% confidence interval: 1.470-18.159, P=0.010). Conclusion. To prevent PSI in Lenke Type 2A AIS patients, surgeons should avoid the combination of non-STF-LTV and high MTC correction in those surgeries with UIV as T2.

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Hidden blood loss in extreme lateral interbody fusion for adult spinal deformity

Mima Y., Yagi M., Suzuki S., Tsuji O., Nagoshi N., Okada E., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2022

ISSN 09492658

Background: Extreme lateral interbody fusion (XLIF) is often used with posterior spinal fixation (PSF) to treat adult spinal deformity (ASD). However, the amount of intraoperative blood loss (IBL) reported for XLIF may underestimate the total blood loss (TBL). The objective of this study was to determine the total perioperative blood loss in XLIF for ASD. Methods: We assessed 30 consecutive ASD patients with Schwab-SRS type L (mean age: 68.7 ± 8.2 years; mean follow-up 2.0 ± 1.3 years) who were treated by multilevel XLIF (mean, 2.5 ± 0.6 levels) followed by PSF after 3–5 days. We calculated the TBL after XLIF by the Gross equation, by hemoglobin (Hb) balance, and by the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula. We defined hidden blood loss (HBL) as the difference between the TBL and IBL. Pearson correlation, Spearman correlation, and multiple logistic regression analysis were performed to investigate the risk factors related to HBL. Results: Post-XLIF blood tests showed a significant decrease in the Hb (from 11.8 ± 1.1 mg/dl to 10.6 ± 1.1 mg/dl) and hematocrit (from 36.0 ± 3.2% to 32.5 ± 3.2%). Although the mean IBL was relatively small (33 ± 52 mL), we calculated the TBL as 291 ± 171 mL (Gross equation) and the HBL as 258 ± 168 mL by Gross equation, which was 8 times greater than the IBL on average. There was no difference in the results obtained using the three methods. Multiple logistic regression analysis indicated preoperative lumber lordosis was the risk factor of high HBL (Odds ratio = 1.085, 95%CI: 1.006–1.170, p = 0.035). Conclusions: The HBL in XLIF was 8 times greater than the IBL. During the perioperative course of correction and fusion surgery for ASD with XLIF, surgeons need to pay attention not to underestimate the TBL.

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Risk factors for early-onset radiographical adjacent segment disease in patients with spondylolytic spondylolisthesis after single-level posterior lumbar interbody fusion

Takeda K., Okada E., Shinozaki Y., Ozaki M., Kono H., Yasuda A., Suzuki S., Tsuji O., Nagoshi N., Yagi M., Fujita N., Ogawa J., Nakamura M., Matsumoto M., Watanabe K.

Spine Journal (Spine Journal) 2022

ISSN 15299430

BACKGROUND CONTEXT: The risk factors for radiographical adjacent segment disease (ASD) in patients with degenerative spondylolisthesis have been previously reported. However, there are only few reports on patients with spondylolytic spondylolisthesis who underwent single-level posterior lumbar interbody fusion (PLIF). PURPOSE: The study aimed to investigate the risk factors for radiographical ASD in patients with L5–S1 spondylolytic spondylolisthesis who underwent single-level PLIF. STUDY DESIGN/SETTING: A retrospective study PATIENT SAMPLE: This study retrospectively reviewed 135 consecutive patients (91 men and 44 women) with symptomatic L5–S1 spondylolytic spondylolisthesis who underwent single-level PLIF. OUTCOME MEASURES: The pre- and postoperative (at the final follow-up) spinopelvic parameters, % slip, sacral slope, lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), PI minus LL (PI − LL), lumbosacral angle, C7 sagittal vertical axis, and thoracic kyphosis were measured using standing radiographs. METHODS: Radiographical ASD was defined as disc height loss (>3 mm), increase of posterior angulation (>5°), or progression of spondylolisthesis (>3 mm) between the pre- and postoperative radiographs. Pfirrmann's classification was used to evaluate disc degeneration. The radiographical parameters and changes between the pre- and postoperative values were evaluated and compared for the non-ASD and ASD groups. Binary logistic regression analysis was performed to evaluate the adjusted associations between each potential explanatory variable and ASD development. RESULTS: The radiographical ASD incidence was 11%. Additionally, 60% of the patients with ASD had radiographical ASD at 1 year and all cases of radiographical ASD in this follow-up period occurred within 3 years after the initial surgery. The mean period of ASD occurrence after initial surgery was 21.7 ± 12.6 months. No patients required reoperation for radiographical ASD. Multivariate analysis revealed that a preoperative (odds ratio [OR], 5.9; 95% confidence interval [CI], 1.2–28.9; p=.03) and a postoperative (OR, 6.5; 95% CI, 1.2–34.5; p=.03) PI − LL of ≥15° were risk factors for radiographical ASD. CONCLUSIONS: Pre- and postoperative PI − LL value mismatch was identified as significant independent risk factors for radiographical ASD in patients with L5–S1 spondylolytic spondylolisthesis. Obtaining larger lordosis at L5–S1 may be the key to preventing radiographical ASD.

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Sublaminar Tethers Significantly Reduce the Risk of Proximal Junctional Failure in Surgery for Severe Adult Spinal Deformity A Propensity Score–matched Analysis

Yagi M., Suzuki S., Okada E., Nori S., Tsuji O., Nagoshi N., Nakamura M., Matsumoto M., Watanabe K.

Clinical Spine Surgery (Clinical Spine Surgery) 2022

ISSN 23800186

Study Design: This was a retrospective case series of prospectively collected data. Objective: The present study first described the effect of sublaminar tethering (SLT) on proximal junctional failure (PJF) in adult spinal deformity (ASD) surgery. Summary of Background Data: PJF is a devastating complication following ASD surgery. Teriparatide administration and spinous process tethering have been reported as alternatives for the prevention of PJF, but a clinically effective prevention strategy is still a matter of debate. Materials and Methods: We used data from an ASD database that included 381 patients with ASD (minimum 2-y follow-up). Among them, the data of patients who had a severe sagittal deformity and had surgery from the lower thoracic spine (T9–T11) to the pelvis were extracted and propensity score matched by age, sex, body mass index, bone mineral density, curve type, sagittal alignment, and fused level to clarify whether SLT prevented the development of PJF [SLT vs. control (CTR); age: 67 ± 7 vs. 66 ± 8 y, T-score: −1.4 ± 0.7 vs. −1.3 ± 0.6, body mass index: 22 ± 4 vs. 22 ± 5 kg/m2, C7 sagittal vertical axis (C7SVA): 12 ± 7 vs. 11 ± 5 cm, pelvic incidence−lumbar lordosis (PI−LL): 51 ± 22 vs. 49 ± 21 degrees, pelvic tilt (PT): 36 ± 10 vs. 34 ± 10 degrees, level fused: 11 ± 2 vs. 11 ± 2]. Sixty-four patients were matched into 32 pairs and compared in terms of the postoperative alignment and frequency of PJF. Results: Two years postoperatively, C7SVA and PT were significantly larger in the CTR group, while no significant difference in PI−LL was found (C7SVA: 3 ± 3 vs. 6 ± 4 cm, P < 0.01, PT: 16± 6 vs. 24± 9 degrees, P 0.01, PI−LL: 7± 9 vs. 11 ± 11 degrees, P=0.22). The proximal junctional angle was significantly greater in the CTR group (proximal junctional kyphosis: 8± 8 vs. 17± 13 degrees, P 0.01). The incidence of PJF was significantly lower in the SLT group (3% vs. 25%, P=0.03), with an odds ratio of 0.1 (95% confidence interval: 0.0-0.8, P=0.03). Conclusion: In the propensity score-matched cohort, the incidence of PJF was significantly lower in the SLT group. SLT is a promising procedure that may reduce the risk of PJF in severe ASD surgery.

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Comparison of Surgical Outcomes After Open- and Double-Door Laminoplasties for Patients with Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study

Nagoshi N., Yoshii T., Egawa S., Sakai K., Kusano K., Nakagawa Y., Hirai T., Wada K., Katsumi K., Fujii K., Kimura A., Furuya T., Kanchiku T., Nagamoto Y., Oshima Y., Nakashima H., Ando K., Takahata M., Mori K., Nakajima H., Murata K., Matsunaga S., Kaito T., Yamada K., Kobayashi S., Kato S., Ohba T., Inami S., Fujibayashi S., Katoh H., Kanno H., Watanabe K., Imagama S., Koda M., Kawaguchi Y., Takeshita K., Nakamura M., Matsumoto M., Yamazaki M., Okawa A.

Spine (Spine) 46 ( 23 ) E1238 - E1245 2021.12

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To evaluate and compare the surgical outcomes after open-door (OD) and double-door (DD) laminoplasties in subjects with cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Although previous studies compared clinical results after OD and DD laminoplasties, they were performed at a single institution with a relatively small sample size targeting mixed pathologies, including cervical spondylotic myelopathy. METHODS: This study was performed by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. A total of 478 patients with myelopathy caused by cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for 2 years. Of these, 41 and 164 patients received OD and DD laminoplasties, respectively. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, and visual analog scale scores. RESULTS: Age, sex, symptom duration, and comorbidities were not significantly different between the groups. Segmental ossification was the most frequent in both the groups. No significant differences in K-line type, canal occupying ratio, C2 to C7 angles, and range of motion were found. Both the procedures reduced the cervical range of motion postoperatively. A comparable frequency of perioperative complications was observed between the groups. The cervical Japanese Orthopaedic Association scores showed a similar improvement at 2 years postopera- tively. The reduction in visual analog scale score for neck pain was favorable in the OD group (P = 0.02), while other pain assessments did not show any significant differences between the groups. The functional outcomes assessed using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire presented equivalent effective rates. CONCLUSION: The results demonstrated almost comparable surgical outcomes between OD and DD laminoplasties. Lamino- plasty is a valuable technique as a therapeutic option for cervical OPLL.Level of Evidence: 2.

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The impact of ossification spread on cervical spine function in patients with ossification of the posterior longitudinal ligament

Katsumi K., Hirai T., Yoshii T., Maki S., Mori K., Nagoshi N., Nishimura S., Takeuchi K., Ushio S., Furuya T., Watanabe K., Nishida N., Watanabe K., Kaito T., Kato S., Nagashima K., Koda M., Ito K., Imagama S., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Watanabe M., Matsumoto M., Nakamura M., Yamazaki M., Okawa A., Kawaguchi Y.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

Ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. The bridging of ossified lesions to the vertebral body gradually increases, thereby decreasing the mobility of the cervical spine; thus, cervical spine function may decrease over time. However, cervical spine function in patients with cervical OPLL has not been evaluated in large prospective studies. Therefore, we conducted a prospective multicenter study to clarify whether ossification spread can influence cervical spine function and quality of life (QOL) in patients with cervical OPLL. In total, 238 patients (162 men, 76 women; mean age, 63.9 years) were enrolled from 16 institutions. Each patient underwent whole spine computed tomography and was evaluated for cervical spine function and QOL using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). In the multivariate regression analysis, a higher neck VAS score and a larger number of bridge formations of OPLL in the whole spine were significant predictors of adverse outcomes related to cervical spine function. This is the first prospective multicenter study to reveal the impact of ossification spread on cervical spine function. These findings are important to understand the natural course of OPLL and can serve as controls when evaluating postoperative cervical spine function.

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Laminectomy with instrumented fusion vs. laminoplasty in the surgical treatment of cervical ossification of the posterior longitudinal ligament: A multicenter retrospective study

Lee J.J., Kim H.C., Jeon H.S., An S.B., Kim T.W., Shin D.A., Yi S., Kim K.N., Yoon D.H., Shin H.C., Nagoshi N., Watanabe K., He D., Hoh D.J., Riew K.D., Shin J.J., Ha Y.

Journal of Clinical Neuroscience (Journal of Clinical Neuroscience) 94 271 - 280 2021.12

ISSN 09675868

Laminectomy with instrumented fusion (LF) has demonstrated better prevention of ossification of posterior longitudinal ligament (OPLL) growth compared to laminoplasty (LP). There remains uncertainty, however, as to which surgical approach is more beneficial with respect to clinical outcomes and complications. We retrospectively reviewed 273 cervical OPLL patients of more than 3 levels, from the two institutions’ databases, who underwent LF or LP between January 1998 and January 2016. Each 273 patient (85 with LF, 188 with LP) was assessed for postoperative neurologic and radiologic outcomes, complications and reoperations. The mean length of follow-up was 40.11 months. There were baseline differences between cohorts. Overall, postoperative JOA recovery rate at last follow up was significantly better in the LP group with similar improvement in visual analog neck score. Postoperative C2-7 Cobb angle was decreased compared to baseline for both LF and LP cohorts, but there was no significant difference between groups. Complications occurred in 19 (22.35%) LF patients, and 11 (5.85%) LP patients, with higher incidence of C5 palsy and instrumentation failure in the LF group. Four LF patients (4.71%) and five LP patients (2.66%) underwent reoperation during the follow up period.

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Grade III intradural extramedullary anaplastic ependymoma managed with near-complete resection and adjuvant radiotherapy: a case report

Ando S., Tsuji O., Nagoshi N., Nori S., Suzuki S., Okada E., Yagi M., Irie R., Watanabe K., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 7 ( 1 ) 2021.12

Introduction: Of the 23 cases of spinal intradural-extramedullary ependymomas which have been reported to date, 11 were diagnosed as anaplastic. Here we present a very rare case of a thoracic intradural-extramedullary (not intramedullary) anaplastic ependymoma in an adult along with a literature review. Case presentation: A 29-year-old man presented with rapidly progressive gait disturbance, a sensory-deficit below the trunk and urination disorders that had begun a few months earlier. Magnetic resonance imaging of his thoracic spine revealed a dorsal-located intradural-extramedullary tumor at T4-5. The rapid deterioration of his symptoms within several months led him to refer to our department for surgery. Within one month the size of tumor increased to involve the T4-6 level, consequently worsening his gait disturbance. He underwent surgery and tumor mass was resected. However, there was leptomeningeal dissemination of the tumor cells on the surface of cord. A near-total resection was therefore achieved. Histopathology revealed the resected specimen had immunoreactivity for EMA/Vimentin/CD56/CD99/S-100/GFAP, with a Ki-67 index of ~35%. These factors led to the diagnosis of anaplastic ependymoma. Seven weeks postoperatively he received adjuvant radiotherapy to the whole brain and the whole spinal cord. He recovered as an independent ambulator without recurrence 1 year postoperatively. Discussion: Because of their rarity, there are no clear treatment or adjuvant therapy guidelines for spinal anaplastic ependymoma. Adjuvant radiotherapy to the whole brain and spinal cord was necessarily indicated after near-total resection. Although the patient’s condition has not recurred 1 year after surgery, careful and serial follow-up is necessary for this individual.

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Determining the validity and reliability of spinopelvic parameters through comparing standing whole spinal radiographs and upright computed tomography images

Fujita N., Yagi M., Watanabe K., Nakamura M., Matsumoto M., Yokoyama Y., Yamada M., Yamada Y., Nagura T., Jinzaki M.

BMC Musculoskeletal Disorders (BMC Musculoskeletal Disorders) 22 ( 1 ) 2021.12

Background: Standing whole spinal radiographs are used to evaluate spinal alignment in adult spinal deformity (ASD), yet some studies have reported that pelvic incidence, pelvic tilt, and thoracic kyphosis (TK) intra- and inter-observer reliability is low. This study aimed to evaluate the accuracy of spinopelvic parameters through comparing standing whole spinal radiographs and upright CT images. Methods: We enrolled 26 patients with ASD. All standing whole spinal posterior/anterior and lateral radiographs and upright whole spinal CT had been obtained in a natural standing position. Two examiners independently measured 13 radiographic parameters. Interclass correlation coefficients (ICCs) were used to analyze measurement intra- and inter-observer reliability. Paired t- and Pearson’s correlation tests were used to analyze validity of the standing whole spinal radiographs. Results: ICCs of upright CT were excellent in both intra- and inter-observer reliability. However, intra-observer ICCs for TK2–12, TK1–5, TK2–5, and TK5–12 on standing lateral radiographs were relatively low, as were inter-observer ICCs for TK2–12, TK1–5, TK2–5, and TK5–12. Concerning TK values, the difference between the radiographs and CT in TK1–12 and TK2–12 were 4.4 ± 3.1 and 6.6 ± 4.6, respectively, and TK values from T2 showed greater measurement error (p < 0.05). Conclusions: Upright CT showed excellent intra- and inter-observer reliability in the measurement of spinopelvic parameters. Measurement of TK with T2 on standing whole spinal radiographs resulted in a greater measurement error of up to 6.6°. Surgeons need to consider this when planning surgery and measuring postoperative TK changes in patients with ASD.

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Clinical application of diffusion tensor tractography to postoperative C5 palsy

Takano M., Tsuji O., Fujiyoshi K., Nagoshi N., Nori S., Suzuki S., Okada E., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 7 ( 1 ) 2021.12

Study design: Diagnostic study. Objective: Although C5 palsy is a well-known potential complication after cervical procedure, the exact pathophysiology remains uncertain. Diffusion tensor tractography (DTT) has recently been proposed as a useful tool to examine quantitatively and non-invasively the pathology of spinal cord disorders. The purpose of this study is to determine the clinical interest of DTT in patients with C5 palsy after cervical laminoplasty. Setting: Single university hospital. Methods: Five patients with C5 palsy out of 108 patients after cervical laminoplasty were subjected to DTT using a 1.5 Tesla magnetic resonance imaging in our hospital between 2010 and 2012. For the tractography, two regions of interest (ROI) were placed at the C5 segmental level and the bilateral C4/5 intervertebral foramen level. Results: The postoperative number of tract fibers at the C5 segmental spinal cord level was significantly increased compared to the preoperative number, despite the C5 palsy. Analyses of two ROIs (at the C5 segmental level and the C4/5 intervertebral foramen level) showed that the number of tract fibers at the palsy side was significantly decreased compared to the intact side. Furthermore, in the patient who spontaneously recovered from C5 palsy within postoperative 6 months, a gradual augmentation of tract fibers was identified at the palsy side. Conclusions: Our findings suggest that DTT can document C5 palsy in detail, as the anatomical region between C5 segmental level and C4/5 intervertebral foramen level was potentially damaged in patients with C5 palsy after laminoplasty.

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Cervical intramedullary recurrent Ewing sarcoma after 10-year disease-free survival in an adult: a case report and review of literature

Fukushima K., Tsuji O., Suzuki S., Nori S., Nagoshi N., Okada E., Yagi M., Emoto K., Nakayama R., Watanabe K., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 7 ( 1 ) 2021.12

Introduction: Intramedullary metastasis of Ewing sarcoma is extremely rare. Here, we report an adult case of cervical intramedullary recurrent Ewing sarcoma after a 10-year disease-free survival after the initial surgery for a thoracic lesion. Case presentation: A 39-year-old man with a history of surgery and chemoradiotherapy for thoracic Ewing sarcoma ten years ago presented with neck pain and incomplete motor paralysis in the right upper extremity, which had suddenly appeared three months before. Cervical magnetic resonance imaging revealed a tear-drop-shaped intramedullary lesion at the C3 level accompanied by diffuse edematous change. Because of the rapid progression of his myelopathy, he underwent surgery for this intramedullary lesion. Intraoperatively, the tumor exhibited an orangish exophytic appearance. The unclearness of the tumor boundary compelled us to perform a partial resection. The histopathology showed the tumor comprised small round atypical cells with immunoreactivity for Nkx2.2 and CD99, diagnosing a metastatic Ewing sarcoma. Postoperatively, although his myelopathy improved transiently and adjuvant chemotherapy radiation was undergone, he died of cranial dissemination of the tumor two months and a half later. Discussion: To our knowledge, 31 cases of primary and only 4 cases of recurrent intramedullary spinal Ewing sarcoma have been reported to date; however, this is the first case of recurrent intramedullary Ewing sarcoma with a 10-year disease-free survival. Sadly, the prognosis of the current case was extremely poor. There is no clear treatment guideline for recurrent intramedullary Ewing sarcoma because of its rarity, and further collection of similar cases would be required.

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Neurological improvement is associated with neck pain attenuation after surgery for cervical ossification of the posterior longitudinal ligament

Koda M., Yoshii T., Egawa S., Sakai K., Kusano K., Nakagawa Y., Hirai T., Wada K., Katsumi K., Kimura A., Furuya T., Maki S., Nagoshi N., Watanabe K., Kanchiku T., Nagamoto Y., Oshima Y., Ando K., Nakashima H., Takahata M., Mori K., Nakajima H., Murata K., Matsunaga S., Kaito T., Yamada K., Kobayashi S., Kato S., Ohba T., Inami S., Fujibayashi S., Katoh H., Kanno H., Takahashi H., Fujii K., Miyagi M., Inoue G., Takaso M., Imagama S., Kawaguchi Y., Takeshita K., Nakamura M., Matsumoto M., Okawa A., Yamazaki M.

Scientific Reports (Scientific Reports) 11 ( 1 ) 2021.12

Although favourable surgical outcomes for myelopathy caused by cervical ossification of the posterior longitudinal ligament (OPLL) have been reported, factors significantly associated with post-operative neck pain attenuation still remain unclear. The primary aim of the present study was to determine factors significantly associated with post-operative neck pain attenuation in patients with cervical OPLL using a prospective multi-centre registry of surgically treated cervical OPLL. Significant postoperative neck pain reduction (50% reduction of neck pain) was achieved in 31.3% of patients. There was no significant difference in neck pain attenuation between surgical procedures. Statistical analyses with univariate analyses followed by stepwise logistic regression revealed neurological recovery as a factor having a significant positive association with post-operative neck pain attenuation (p = 0.04, odds ratio 5.68 (95% confidence interval: 1.27–22.2)). In conclusion, neurological recovery was an independent factor having a significant positive association with post-operative neck pain attenuation in patients with cervical myelopathy caused by OPLL who underwent cervical spine surgery.

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Surgical resection of arteriovenous fistula at the cauda equina

Shimizu T., Nagoshi N., Akiyama T., Suzuki S., Nori S., Tsuji O., Okada E., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 7 ( 1 ) 2021.12

Introduction: Although spinal arteriovenous fistula (AVF) has been reported widely, AVF at the cauda equina is quite rare. We described a case of AVF at the cauda equina that was fed by the distal radicular artery (DRA). Case presentation: A 50-year-old woman presented with sudden weakness of the lower extremities. Magnetic resonance imaging (MRI) revealed a lesion with a highly intense signal at the conus medullaris, which was surrounded by several low-intensity signals (flow voids). Digital subtraction angiography revealed AVF at the cauda equina and that it was fed by the DRA, which was directly fed by the L3 segmental artery. We performed surgical resection of the AVF while monitoring motor-evoked potentials. The patient’s postoperative course was uneventful, and her neurological symptoms gradually resolved. MRI 2 years after surgery showed the disappearance of both intramedullary edema and the flow voids. Discussion: For the AVF, located at the cauda equina and fed by the DRA in this case, surgical resection or endovascular embolization could have been selected. We performed open surgery to achieve complete obliteration of the AVF, which led to postoperative functional recovery without any adverse events. However, only a limited number of AVFs at the level of the cauda equina have been reported, and treatment standards have not been established. Further studies of AVFs at the cauda equina are necessary to clarify the epidemiological characteristics and clinical outcomes with an appropriate sample size.

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Surgical and Functional Outcomes of Expansive Open-Door Laminoplasty for Patients With Mild Kyphotic Cervical Alignment

Nagoshi N., Nori S., Tsuji O., Suzuki S., Okada E., Yagi M., Nakamura M., Matsumoto M., Watanabe K.

Neurospine (Neurospine) 18 ( 4 ) 749 - 757 2021.12

ISSN 25866583

Objective: To evaluate the cervical dynamics, neurological function, pain, and quality of life in patients with mild cervical kyphotic alignment who underwent expansive unilateral open-door laminoplasty (ELAP). Methods: In this retrospective single-center study, we reviewed the surgical outcomes of 80 patients with cervical spondylotic myelopathy who were followed for at least 2 years. The patients were categorized into the preoperative kyphotic group (C2–7 angle < 0°) and non-kyphotic group (angle ≥ 0°). We compared clinical information, radiographic parameters, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOAC-MEQ) scores, and cervical Japanese Orthopaedic Association (JOA) scores between the groups. Results: The kyphotic and nonkyphotic groups comprised 17 and 63 patients, respectively. The preoperative C2–7 angles were-3.7° in the kyphotic group and 15.4° in the nonky-photic group (p < 0.01). In the kyphotic group, kyphotic alignment improved to lordosis at the final follow-up (2.6°, p = 0.01). The preoperative (16.4° vs. 24.1°, p < 0.01) and final-follow-up (17.8° vs. 24.5°, p < 0.01) C7 slopes were significantly smaller in the kyphotic group. ELAP reduced pain in the arms or hands (p = 0.02) and improved the JOA scores (p < 0.01) in the kyphotic group. Patient-reported outcomes assessed using the JOACMEQ showed comparable effective rates in both groups. Conclusion: Patients with mild cervical kyphosis showed smaller C7 slopes as a compensatory mechanism. Kyphotic angles significantly improved to lordosis after ELAP, resulting in favorable clinical outcomes. ELAP is a useful surgical option for patients even if they present mild kyphotic cervical angles.

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Recurrence of cervical intramedullary gliofibroma

Tokunaga K., Nagoshi N., Ohara K., Shibuya M., Suzuki S., Tsuji O., Okada E., Fujita N., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 7 ( 1 ) 2021.12

Introduction: Gliofibroma is a rare tumor that develops in the brain and spinal cord. Due to the rarity of its nature, its pathophysiology and appropriate treatment remain elusive. We report a case of intramedullary spinal cord gliofibroma that was surgically treated multiple times. This report is of great significance because this is the first case of recurrence of this tumor. Case presentation: A 32-year-old woman complained of gait disturbance and was referred to our institution. At the age of 13 years, she was diagnosed with intramedullary gliofibroma and underwent gross total resection (GTR) in another hospital. Based on imaging findings, tumor recurrence was suspected at the level of cervical spinal cord, and surgery was performed. However, the resection volume was limited to 50% because the boundary between the tumor and spinal cord tissue was unclear and intraoperative neuromonitoring alerted paralysis. At 1 year postoperatively, the second surgery was performed to try to resect the residual tumor, but subtotal resection was achieved at most. At 2 years after the final surgery, no tumor recurrence was observed, and neurologic function was maintained to gait with cane. Discussion: Although complete resection is desirable for this rare tumor at the initial surgery, there is a possibility to recur even after GTR with long-term follow-up. During surgical treatment for tumor recurrence, fair adhesion to the spinal cord is expected, and reoperation and/or adjuvant therapy might be considered in the future if the tumor regrows and triggers neurological deterioration.

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Factors significantly associated with postoperative neck pain deterioration after surgery for cervical ossification of the posterior longitudinal ligament: Study of a cohort using a prospective registry

Journal of Clinical Medicine (Journal of Clinical Medicine) 10 ( 21 ) 2021.11

Postoperative neck pain has been reported as an unsolved postoperative complication of surgery for cervical ossification of the posterior longitudinal ligament (OPLL). The aim of the present study was to elucidate factors having a significant association with postoperative deterioration of neck pain in cervical OPLL patients. We studied a cohort of patients in a prospective registry of 478 patients who had undergone cervical spine surgery for cervical OPLL. We excluded those without evaluation of preoperative neck pain. Therefore, 438 patients were included in the present study. Neck pain was evaluated with the visual analogue scale (VAS, 0–100 mm). Postoperative neck pain deterioration was defined as a ≥20 mm increase of VAS neck pain. Patient factors, neurological status, imaging factors and surgical factors were assessed. Univariate analyses followed by multivariate analysis using stepwise logistic regression was performed. Six months after surgery, 50 (11.6%) patients showed postoperative neck pain deterioration and 76 (17.4%) patients showed postoperative neck pain deterioration 2 years after surgery. Six months after surgery, the rate of neck pain deterioration was significantly higher in patients who had undergone posterior surgery. Two years after surgery, the number of levels fused was significantly correlated with neck pain deterioration.

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Risk factors for delayed diagnosis of spinal fracture associated with diffuse idiopathic skeletal hyperostosis: A nationwide multiinstitution survey

Kobayashi K., Okada E., Yoshii T., Tsushima M., Yamada T., Watanabe K., Katsumi K., Hiyama A., Katoh H., Watanabe M., Nakagawa Y., Okada M., Endo T., Shiraishi Y., Takeuchi K., Matsunaga S., Maruo K., Sakai K., Kobayashi S., Ohba T., Wada K., Ohya J., Mori K., Nishimura H., Tsuji T., Watanabe K., Okawa A., Matsumoto M., Imagama S.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 26 ( 6 ) 968 - 973 2021.11

ISSN 09492658

Background: Patients with DISH are susceptible to spinal fractures and subsequent neurological impairment, including after minor trauma. However, DISH is often asymptomatic and fractures may have minimal symptoms, which may lead to delayed diagnosis. The purpose of this study was to identify risk factors for delayed diagnosis of spinal fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH). Methods: The subjects were 285 patients with DISH surgically treated at 18 medical centers from 2005 to 2015. Cause of injury, imaging findings, neurological status at the times of injury and first hospital examination, and the time from injury to diagnosis were recorded. A delayed diagnosis was defined as that made >24 h after injury. Results: Main causes of injury were minor trauma due to a fall from a standing or sitting position (51%) and high-energy trauma due to a fall from a high place (29%) or a traffic accident (12%). Delayed diagnosis occurred in 115 patients (40%; 35 females, 80 males; mean age 76.0 ± 10.4 years), while 170 (60%; 29 females, 141 males; mean age 74.6 ± 12.8 years) had early diagnosis. Delayed group had a significantly higher rate of minor trauma (n = 73, 63% vs. n = 73, 43%), significantly more Frankel grade E (intact neurological status) cases at the time of injury (n = 79, 69% vs. n = 73, 43%), and greater deterioration of Frankel grade from injury to diagnosis (34% vs. 8%, p < 0.01). In multivariate analysis, a minor trauma fall (OR 2.08; P < 0.05) and Frankel grade E at the time of injury (OR 2.29; P < 0.01) were significantly associated with delayed diagnosis. Conclusion: In patients with DISH, it is important to keep in mind the possibility of spinal fracture, even in a situation in which patient sustained only minor trauma and shows no neurological deficit. This is because delayed diagnosis of spinal fracture can cause subsequent neurological deterioration.

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Risk predictors of perioperative complications for the palliative surgical treatment of spinal metastasis

Isogai N., Yagi M., Nishimura S., Nishida M., Mima Y., Hosogane N., Suzuki S., Fujita N., Okada E., Nagoshi N., Tsuji O., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 26 ( 6 ) 1107 - 1112 2021.11

ISSN 09492658

Background: The complication rate for palliative surgery in spinal metastasis is relatively high, and major complications can impair the patient's activities of daily living. However, surgical indications are determined based primarily on the prognosis of the cancer, with the risk of complications not truly considered. We aimed to identify the risk predictors for perioperative complications in palliative surgery for spinal metastasis. Methods: A multicentered, retrospective review of 195 consecutive patients with spinal metastasis who underwent palliative surgeries with posterior procedures from 2001 to 2016 was performed. We evaluated the type and incidence of perioperative complications within 14 days after surgery. Patients were categorized into either the complication group (C) or no-complication group (NC). Univariate and multivariate analyses were used to identify potential predictors for perioperative complications. Results: Thirty patients (15%) experienced one or more complications within 14 days of surgery. The most frequent complications were surgical site infection (4%) and motor weakness (3%). A history of diabetes mellitus (C; 37%, NC; 9%: p < 0.01) and surgical time over 300 min (C; 27%, NC; 12%: p < 0.05) were significantly associated with complications according to univariate analysis. Increased blood loss and non-ambulatory status were determined to be potential risk factors. Of these factors, multivariate logistic regression revealed that a history of diabetes mellitus (OR: 6.6, p < 0.001) and blood loss over 1 L (OR: 2.7, p < 0.05) were the independent risk factors for perioperative complications. There was no difference in glycated hemoglobin A1c between the diabetes patients with and without perioperative complications. Conclusions: Diabetes mellitus should be used for the risk stratification of surgical candidates regardless of the treatment status, and strict prevention of bleeding is needed in palliative surgeries with posterior procedures to mitigate the risk of perioperative complications.

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Association between severity of diffuse idiopathic skeletal hyperostosis and ossification of other spinal ligaments in patients with ossification of the posterior longitudinal ligament

Nishimura S., Hirai T., Nagoshi N., Yoshii T., Hashimoto J., Mori K., Maki S., Katsumi K., Takeuchi K., Ushio S., Furuya T., Watanabe K., Nishida N., Kaito T., Kato S., Nagashima K., Koda M., Nakashima H., Imagama S., Murata K., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Watanabe M., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Matsukura Y., Inose H., Yamazaki M., Watanabe K., Matsumoto M., Nakamura M., Okawa A., Kawaguchi Y.

Journal of Clinical Medicine (Journal of Clinical Medicine) 10 ( 20 ) 2021.10

Background: Although diffuse idiopathic skeletal hyperostosis (DISH) is known to coexist with the ossification of spinal ligaments (OSLs), details of the radiographic relationship remain unclear. Methods: We prospectively collected data of 239 patients with symptomatic cervical ossification of the posterior longitudinal ligament (OPLL) and analyzed the DISH severity on whole-spine computed tomography images, using the following grades: grade 0, no DISH; grade 1, DISH at T3–T10; grade 2, DISH at both T3–T10 and C6–T2 and/or T11–L2; and grade 3, DISH beyond C5 and/or L3. Ossification indices were calculated as the sum of vertebral and intervertebral levels with OSL for each patient. Results: DISH was found in 107 patients (44.8%), 65 (60.7%) of whom had grade 2 DISH. We found significant associations of DISH grade with the indices for cervical OPLL (r = 0.45, p < 0.0001), thoracic ossification of the ligamentum flavum (OLF; r = 0.41, p < 0.0001) and thoracic ossification of the supra/interspinous ligaments (OSIL; r = 0.53, p < 0.0001). DISH grade was also correlated with the index for each OSL in the whole spine (OPLL: r = 0.29, p < 0.0001; OLF: r = 0.40, p < 0.0001; OSIL: r = 0.50, p < 0.0001). Conclusion: The DISH grade correlated with the indices of OSL at each high-prevalence level as well as the whole spine.

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Efficacy of hyaluronic acid on intervertebral disc inflammation: An in vitro study using notochordal cell lines and human disc cells

Yamamoto T., Suzuki S., Fujii T., Mima Y., Watanabe K., Matsumoto M., Nakamura M., Fujita N.

Journal of Orthopaedic Research (Journal of Orthopaedic Research) 39 ( 10 ) 2197 - 2208 2021.10

ISSN 07360266

Hyaluronic acid (HA) is widely recognized as a therapeutic target and currently used in medicine. However, HA metabolism during intervertebral disc degeneration (IVDD) has not been completely elucidated. This study aimed to evaluate the efficacy of HA on intervertebral disc (IVD) inflammation and identify the main molecules modulating HA degradation in IVDs. To assess HA function in IVD cells in vitro, we treated human disc cells and U-CH1-N cells, a notochordal nucleus pulposus cell line, with HA or hyaluronidase. Real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis showed that tumor necrosis factor alpha (TNF-α)-mediated induction of the expression of TNF-α and cyclooxygenase-2 (COX2) was clearly neutralized by HA treatment, and the expression of TNF-α and COX2 was significantly induced by hyaluronidase treatment in both cell types. Additionally, Western blot analysis showed that hyaluronidase-induced phosphorylation of p38 and Erk1/2, and that TNF-α-mediated phosphorylation of p38 and Erk1/2 was clearly reduced by HA addition. In degenerating human IVD samples, immunohistochemistry for hyaluronidase showed that the expression of hyaluronidases including HYAL1, HYAL2, and cell migration-inducing protein (CEMIP) tended to increase in accordance with IVDD. In particular, HYAL1 showed statistically significant differences. In vitro study also confirmed a similar phenomenon that TNF-α treatment increased both messenger RNA and protein expression in both cell types. Our results demonstrated that HA could potentially suppress IVDD by regulating p38 and Erk1/2 pathways, and that the expression of HYAL1 was correlated with IVDD progression. These findings indicated that HYAL1 would be a potential molecular target for suppressing IVDD by controlling HA metabolism.

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Does Selective Posterior Correction and Fusion Surgery Influence Cervical Sagittal Alignment in Patient with Lenke Type 5 Adolescent Idiopathic Scoliosis?-A 5-year Follow-up Retrospective Cohort Study

Okubo T., Yagi M., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 46 ( 18 ) E976 - E984 2021.09

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: The aim of this study was to examine the changes in cervical sagittal alignment (CSA) following surgical correction in a patient with Lenke type 5 adolescent idiopathic scoliosis (AIS) and evaluate any possible factors influencing postoperative CSA. SUMMARY OF BACKGROUND DATA: Few studies have assessed the association between CSA and thoracic or lumbar sagittal alignment in AIS patients with major thoracolumbar/lumbar curve who underwent posterior correction and fusion surgery. METHODS: Sixty-six patients with Lenke type 5 AIS (two males and 64 females, the mean age at surgery of 16.2 years) were included in this study. They were followed up for minimum 5 years after surgery. Multiple linear regression analysis was used to evaluate possible factors influencing the postoperative CSA. To determine the influence of upper end vertebra (UEV) level on postoperative CSA, the subjects were divided into two groups according to UEV level of ≥T9 or ≤T10. The outcome variables were compared between the two groups and analyzed for changes in various spinal sagittal profiles using radiographic outcomes. RESULTS: Multiple linear regression analysis revealed that preoperative T10-L2 kyphosis and LL were significantly correlated with postoperative C2-7 lordosis. However, CSA did not significantly change at 5 years after surgery. Sub-analysis of the cohort revealed that in the UEV ≥T9 group, the mean thoracic kyphosis significantly increased from 20.3° ± 10.6° to 24.0° ± 8.9° and the mean C2-7 lordosis also significantly increased from -12.5° ± 8.3° to -4.3° ± 10.3° at 5-year postoperatively. SRS-22 outcomes were comparable between the groups. CONCLUSION: We indicated that the CSA was not influenced by surgical correction in most Lenke type 5 AIS patients. However, in a patient whose UEV was located at T9 or higher levels, CSA was influenced through the changes in thoracic kyphosis following posterior correction surgery.Level of Evidence: 4.

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Cobalt-Chromium Alloy Has Superior Antibacterial Effect Than Titanium Alloy: In Vitro and In Vivo Studies

Watanabe K., Fukuzaki S., Sugino A., Benson N., Metcalf N., Nakamura M., Matsumoto M.

Spine (Spine) 46 ( 17 ) E911 - E915 2021.09

STUDY DESIGN: In vitro and in vivo laboratory studies. OBJECTIVE: This study aimed to compare bacterial survival on titanium alloy (Ti) and cobalt-chromium alloy (CC) using in vitro and in vivo experiments. SUMMARY OF BACKGROUND DATA: Spinal implants are frequently manufactured from Ti and CC. These foreign materials are thought to be susceptible to biofilm formation that contributes to the development of surgical site infections. Certain metals (i.e., silver, cobalt) are known to have antibacterial properties. METHODS: In the in vitro study, discs made of Ti or CC were incubated with one of two common bacteria: Staphylococcus aureus (S. aureus) and Propionibacterium acnes (P. acnes). After incubation, discs were assessed to determine the number of viable bacterial cells. In the in vivo study, the discs that were made of CC or Ti were implanted into the subcutaneous layer of BALB/c mice. After skin closure, a suspension including either S. aureus or P. acnes was directly inoculated on the implanted discs. The discs were retrieved and analyzed to determine the number of viable bacteria at 0.5, 1, and 3 days after inoculation. RESULTS: The number of viable S. aureus cultured from the CC discs was 0.9 ± 0.2 × 103 CFU/disc, which was significantly lower than the cultured Ti discs (114.8 ± 18.3 × 103 CFU/disc). Moreover, a significantly lower mean number of P. acnes were cultured with CC (1.9 ± 1.2 × 103 CFU/disc) compared with the Ti (180.0 ± 72.1 × 103 CFU/disc). The in vivo infection model testing against S. aureus or P. acnes showed a significantly lower number of viable S. aureus or P. acnes on CC discs than Ti discs. The result was seen at all measured time points. CONCLUSION: CC suppressed S. aureus and P. acnes proliferation compared with Ti in vitro and in an in vivo infection model.Level of Evidence: N/A.

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Associations between clinical findings and severity of diffuse idiopathic skeletal hyperostosis in patients with ossification of the posterior longitudinal ligament

Hirai T., Nishimura S., Yoshii T., Nagoshi N., Hashimoto J., Mori K., Maki S., Katsumi K., Takeuchi K., Ushio S., Furuya T., Watanabe K., Nishida N., Watanabe K., Kaito T., Kato S., Nagashima K., Koda M., Nakashima H., Imagama S., Murata K., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Watanabe M., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Matsumoto M., Nakamura M., Yamazaki M., Matsukura Y., Inose H., Okawa A., Kawaguchi Y.

Journal of Clinical Medicine (Journal of Clinical Medicine) 10 ( 18 ) 2021.09

Background: This study investigated how diffuse idiopathic skeletal hyperostosis (DISH) influences clinical characteristics in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Although DISH is considered unlikely to promote neurologic dysfunction, this relationship remains unclear. Methods: Patient data were prospectively collected from 16 Japanese institutions. In total, 239 patients with cervical OPLL were enrolled who had whole-spine computed tomography images available. The primary outcomes were visual analog scale pain scores and the results of other self-reported clinical questionnaires. Correlations were sought between clinical symptoms and DISH using the following grading system: 1, DISH at T3-T10; 2, DISH at both T3–10 and C6–T2 and/or T11–L2; and 3, DISH beyond the C5 and/or L3 levels. Results: DISH was absent in 132 cases, grade 1 in 23, grade 2 in 65, and grade 3 in 19. There were no significant correlations between DISH grade and clinical scores. However, there was a significant difference in the prevalence of neck pain (but not in back pain or low back pain) among the three grades. Interestingly, DISH localized in the thoracic spine (grade 1) may create overload at the cervical spine and lead to neck pain in patients with cervical OPLL. Conclusion: This study is the first prospective multicenter cross-sectional comparison of subjective outcomes in patients with cervical OPLL according to the presence or absence of DISH. The severity of DISH was partially associated with the prevalence of neck pain.

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Surgical Site Infection Following Primary Definitive Fusion for Pediatric Spinal Deformity: A Multicenter Study of Rates, Risk Factors, and Pathogens

Watanabe K., Yamaguchi T., Suzuki S., Suzuki T., Nakayama K., Demura S., Taniguchi Y., Yamamoto T., Sugawara R., Sato T., Fujiwara K., Murakami H., Akazawa T., Kakutani K., Hirano T., Yanagida H., Watanabe K., Matsumoto M., Uno K., Kotani T., Takeshita K., Ohara T., Kawakami N.

Spine (Spine) 46 ( 16 ) 1097 - 1104 2021.08

STUDY DESIGN: A retrospective multicenter study. OBJECTIVE: To determine the surgical site infection (SSI) rate, associated risk factors, and causative pathogens in pediatric patients with spinal deformity. SUMMARY OF BACKGROUND DATA: There have been no extensive investigations of the risk factors for SSI in Japan. METHODS: Demographic data, radiographic findings, and the incidence of SSI were retrospectively analyzed in 1449 pediatric patients who underwent primary definitive fusion surgery for spinal deformity at any of 15 institutions from 2015 to 2017. SSI was defined according to the US Centers for Disease Control and Prevention guideline. RESULTS: The incidence of all SSIs was 1.4% and that of deep SSIs was 0.76%. The most common pathogenic microbes were methicillin-resistant staphylococci (n = 5) followed by gram-negative rods (n = 4), methicillin-sensitive staphylococci (n = 1), and others (n = 10). In univariate analysis, younger age, male sex, a diagnosis of kyphosis, type of scoliosis, American Society of Anesthesiologists (ASA) class ≥3, mental retardation urinary incontinence, combined anterior-posterior fusion, greater magnitude of kyphosis, three-column osteotomy, use of blood transfusion, and number of antibiotic administration were associated with the likelihood of SSI (all P < 0.05). Multivariate logistic regression analysis identified the following independent risk factors for SSI: syndromic scoliosis etiology (vs. idiopathic scoliosis; adjusted odds ratio [OR] 16.106; 95% confidence interval [CI] 2.225-116.602), neuromuscular scoliosis etiology (vs. idiopathic scoliosis; adjusted OR 11.814; 95% CI 1.109-125.805), ASA class 3 (vs. class 2; adjusted OR 15.231; 95% CI 1.201-193.178), and administration of antibiotic therapy twice daily (vs. three times daily; adjusted OR 6.121; 95% CI 1.261-29.718). CONCLUSION: The overall infection rate was low. The most common causative bacteria were methicillin-resistant followed by gram-negative rods. Independent risk factors for SSI in pediatric patients undergoing spinal deformity surgery were scoliosis etiology, ASA class 3, and administration of antibiotic therapy twice daily.Level of Evidence: 3.

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How Preoperative Motor Weakness Affects the Extent of Recovery After Elective Spine Surgery in Patients with Degenerative Lumbar Spinal Stenosis

Yagi M., Suzuki S., Nori S., Okada E., Tsuji O., Nagoshi N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 46 ( 16 ) 1118 - 1127 2021.08

STUDY DESIGN: Retrospective review. OBJECTIVE: This study sought to determine how baseline motor weakness (MW) affects elective spine surgery in patients with degenerative lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Favorable clinical outcomes have been described for elective spine surgery in patients with LSS. However, the way preoperative MW affects the patient's health-related quality of life (HRQoL) after surgery is not well understood. METHODS: A retrospective review of prospectively collected data from 305 surgically treated patients with LSS who had 2-year follow-up was performed (age 71 ± 9 yrs, male 62%). Demographic, radiographic, and clinical outcomes were analyzed at baseline and at 1-year, 2-year, and 3-year postoperation. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire was used to assess the HRQoLs. The HRQoLs were compared between those with or without preop MW. Adjusted multivariate logistic regression analyses were performed to determine whether MW affected HRQoLs. RESULTS: One hundred sixteen patients (38%) were categorized as MW+. The patient background including age, sex, presence of degenerative spondylolisthesis, type of surgery, and presence of neurological claudication were similar between the two groups. However, the 1-, 2-, and 3-year postoperative visual analogue scale of back pain, leg pain, leg numbness, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire lumbar function, social life, mental health, and walking ability were all inferior in the MW+ group, whereas a similar percentage of patients achieved a minimum clinically important difference in all subdomains at 3 years. The adjusted multivariate logistic regression analyses showed that having ≥2 muscles with MW, and severity of MW (manual motor test grade) were independent risk factors for both difficulty climbing stairs and walking >15 minutes. (muscles with MW≥2; stair climbing: OR 6.4[2.3-17.4], walking: OR 3.2[1.4-7.3], severity of MW; stair climbing: OR 2.5[1.4-4.4], walking: OR 2.2[1.3-3.7]). CONCLUSION: The patients with baseline MW had inferior HRQoL for up to 3 years compared with that of those without MW; however, the amount of improvement in HRQoL was comparable. Timely follow-up is important to find out the deterioration of motor function.Level of Evidence: 4.

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Impact of diabetes mellitus on cervical spine surgery for ossification of the posterior longitudinal ligament

Kimura A., Takeshita K., Yoshii T., Egawa S., Hirai T., Sakai K., Kusano K., Nakagawa Y., Wada K., Katsumi K., Fujii K., Furuya T., Nagoshi N., Kanchiku T., Nagamoto Y., Oshima Y., Nakashima H., Ando K., Takahata M., Mori K., Nakajima H., Murata K., Matsunaga S., Kaito T., Yamada K., Kobayashi S., Kato S., Ohba T., Inami S., Fujibayashi S., Katoh H., Kanno H., Watanabe K., Imagama S., Koda M., Kawaguchi Y., Nakamura M., Matsumoto M., Yamazaki M., Okawa A.

Journal of Clinical Medicine (Journal of Clinical Medicine) 10 ( 15 ) 2021.08

Ossification of the posterior longitudinal ligament (OPLL) is commonly associated with diabetes mellitus (DM); however, the impact of DM on cervical spine surgery for OPLL remains unclear. This study was performed to evaluate the influence of diabetes DM on the outcomes following cervical spine surgery for OPLL. In total, 478 patients with cervical OPLL who underwent surgical treatment were prospectively recruited from April 2015 to July 2017. Functional measurements were conducted at baseline and at 6 months, 1 year, and 2 years after surgery using JOA and JOACMEQ scores. The incidence of postoperative complications was categorized into early (_30 days) and late (>30 days), depending on the time from surgery. From the initial group of 478 patients, 402 completed the 2-year follow-up and were included in the analysis. Of the 402 patients, 127 (32%) had DM as a comorbid disease. The overall incidence of postoperative complications was significantly higher in patients with DM than in patients without DM in both the early and late postoperative periods. The patients with DM had a significantly lower JOA score and JOACMEQ scores in the domains of lower extremity function and quality of life than those without DM at the 2-year follow-up.

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Polygenic Risk Score of Adolescent Idiopathic Scoliosis for Potential Clinical Use

Otomo N., Lu H.F., Koido M., Kou I., Takeda K., Momozawa Y., Kubo M., Kamatani Y., Ogura Y., Takahashi Y., Nakajima M., Minami S., Uno K., Kawakami N., Ito M., Sato T., Watanabe K., Kaito T., Yanagida H., Taneichi H., Harimaya K., Taniguchi Y., Shigematsu H., Iida T., Demura S., Sugawara R., Fujita N., Yagi M., Okada E., Hosogane N., Kono K., Nakamura M., Chiba K., Kotani T., Sakuma T., Akazawa T., Suzuki T., Nishida K., Kakutani K., Tsuji T., Sudo H., Iwata A., Kaneko K., Inami S., Kochi Y., Chang W.C., Matsumoto M., Watanabe K., Ikegawa S., Terao C.

Journal of Bone and Mineral Research (Journal of Bone and Mineral Research) 36 ( 8 ) 1481 - 1491 2021.08

ISSN 08840431

Adolescent idiopathic scoliosis (AIS) is a common disease causing three-dimensional spinal deformity in as many as 3% of adolescents. Development of a method that can accurately predict the onset and progression of AIS is an immediate need for clinical practice. Because the heritability of AIS is estimated as high as 87.5% in twin studies, prediction of its onset and progression based on genetic data is a promising option. We show the usefulness of polygenic risk score (PRS) for the prediction of onset and progression of AIS. We used AIS genomewide association study (GWAS) data comprising 79,211 subjects in three cohorts and constructed a PRS based on association statistics in a discovery set including 31,999 female subjects. After calibration using a validation data set, we applied the PRS to a test data set. By integrating functional annotations showing heritability enrichment in the selection of variants, the PRS demonstrated an association with AIS susceptibility (p = 3.5 × 10−40 with area under the receiver-operating characteristic [AUROC] = 0.674, sensitivity = 0.644, and specificity = 0.622). The decile with the highest PRS showed an odds ratio of as high as 3.36 (p = 1.4 × 10−10) to develop AIS compared with the fifth in decile. The addition of a predictive model with only a single clinical parameter (body mass index) improved predictive ability for development of AIS (AUROC = 0.722, net reclassification improvement [NRI] 0.505 ± 0.054, p = 1.6 × 10−8), potentiating clinical use of the prediction model. Furthermore, we found the Cobb angle (CA), the severity measurement of AIS, to be a polygenic trait that showed a significant genetic correlation with AIS susceptibility (rg = 0.6, p = 3.0 × 10−4). The AIS PRS demonstrated a significant association with CA. These results indicate a shared polygenic architecture between onset and progression of AIS and the potential usefulness of PRS in clinical settings as a predictor to promote early intervention of AIS and avoid invasive surgery. © 2021 American Society for Bone and Mineral Research (ASBMR).

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The effectiveness of chemonucleolysis with condoliase for treatment of painful lumbar disc herniation

Okada E., Suzuki S., Nori S., Tsuji O., Nagoshi N., Yagi M., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 26 ( 4 ) 548 - 554 2021.07

ISSN 09492658

Background: Chemonucleolysis with condoliase, which degrades chondroitin sulfate, could be a new, minimally invasive therapeutic option for patients with lumbar disc herniation (LDH). The purpose of this study was to analyze prognostic factors for clinical outcomes in LDH patients subjected to chemonucleolysis with condoliase. Methods: Inclusion criteria for this procedure were 1) 18–70 years of age; 2) unilateral leg pain and positive straight leg raise (SLR) (<70°) or femoral nerve stretching test; 3) subligamentous extrusion verified on magnetic resonance imaging; 4) neurological symptoms consistent with a compressed nerve root on magnetic resonance imaging (MRI) images; and 5) minimum six months of follow-up. In total, 82 patients (55 men, 27 women; mean age, 47.2 ± 15.5 years; mean follow-up, 9.1 ± 3.0 months) who underwent chemonucleolysis with condoliase for painful LDH were included. An improvement of 50% or more in the Visual analogue scale (VAS) of leg pain was classified as effective. Results: Seventy patients (85.4%) were classified into the effective (E) group and 12 patients (14.6%) into the less-effective (L) group. Surgical treatment was required in four patients. No severe adverse complications were reported; 41.3% of the patients developed disc degeneration of Pfirrmann grade 1 or more at the injected disc level. Univariate analysis revealed that young age (p = 0.036), without history of epidural or nerve root block (p = 0.024), and injection into the central portion of the intervertebral disc (p = 0.014) were significantly associated with clinical effectiveness. A logistic regression analysis revealed that injection into the central portion of the intervertebral disc (p = 0.049; odds ratio, 4.913; 95% confidence interval, 1.006–26.204) was significantly associated with clinical effectiveness. Conclusions: Chemonucleolysis with condoliase is a safe and effective treatment for painful LDH; 85.4% of the patients showed improvement after the treatment without severe adverse events. To obtain the best outcome, condoliase should be injected into the center of the intervertebral disc.

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Characterization of Patients with Poor Risk for Clinical Outcomes in Adult Symptomatic Lumbar Deformity Surgery

Yagi M., Michikawa T., Suzuki S., Okada E., Nori S., Tsuji O., Nagoshi N., Asazuma T., Hosogane N., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 46 ( 12 ) 813 - 821 2021.06

STUDY DESIGN: Retrospective review of 159 surgically treated consecutive adult symptomatic lumbar deformity (ASLD) (65 ± 9 years, female: 94%) from a multicenter database. OBJECTIVE: The aim of this study was to provide a comprehensive analysis of the risk of a poor clinical outcome in ASLD surgery. SUMMARY OF BACKGROUND DATA: Poor-risk patients with ASLD remain poorly characterized. METHODS: ASLD was defined as age >40 years with a lumbar curve ≥30° or C7SVA ≥5 cm and Scoliosis Research Society 22 (SRS22) pain or function <4. Poor outcome was defined as 2y SRS22 total <4 or pain, function or satisfaction ≤3. The outcomes of interest included age, sex, body mass index, bone mineral density, Schwab-SRS type, frailty, history of arthroplasty, upper-instrumented vertebral, lower-instrumented vertebral, levels involved, pedicle subtraction osteotomy, lumbar interbody fusion, sagittal alignment, global alignment and proportion (GAP) score, baseline SRS22r score, estimated blood loss, time of surgery, and severe adverse event (SAE). Poisson regression analyses were performed to identify the independent risks for poor clinical outcome. A patient was considered at poor risk if the number of risks was >4. RESULTS: All SRS22 domains were significantly improved after surgery. In total, 21% (n = 34) reported satisfaction ≤3 and 29% (n = 46) reported pain or function ≤3. Poisson regression analysis revealed that frailty (odds ratio [OR]: 0.2 [0.1-0.8], P = .03), baseline mental-health (OR: 0.6 [0.4-0.9], P = .01) and function (OR: 1.9 [1.0-3.6], P < .01), GAP score (OR: 4.6 [1.1-18.7], P = .03), and SAE (OR: 3.0 [1.7-5.2], P < .01) were identified as independent risk for poor clinical outcome. Only 17% (n = 6) of the poor-risk patients reached SRS22 total score >4.0 at 2 years. CONCLUSION: The overall clinical outcome was favorable for ASLD surgery. Poor-risk patients continue to have inferior outcomes, and alternative treatment strategies are needed to help improve outcomes in this patient population. Recognition and optimization of modifiable risk factors, such as physical function and mental health, and reduced SAEs may improve overall clinical outcomes of ASLD surgery.Level of Evidence: 3.

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Spontaneous reduction of chiari malformation and syringomyelia after posterior spinal fusion for scoliosis

Iwami T., Watanabe K., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Yagi M., Fujita N., Nakamura M., Matsumoto M.

JBJS Case Connector (JBJS Case Connector) 11 ( 2 ) 2021.06

ISSN 21603251

Case: A 22-year-old skeletally mature man with scoliosis accompanied by syringomyelia associated with Chiari malformation type 1 was presented to our hospital. Because the maximal syrinx/cord ratio was small, and he had no neurological deficit, he underwent corrective surgery without the treatment of the syringomyelia. Conclusion: The scoliosis was corrected without any neurological complications. Magnetic resonance imaging taken 8 days after the surgery showed the reduction of the size of the syringomyelia. The syringomyelia almost disappeared at the 8-year follow-up.

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The Long-term Impact of Whiplash Injuries on Patient Symptoms and the Associated Degenerative Changes Detected Using MRI: A Prospective 20-year Follow-up Study Comparing Patients with Whiplash-associated Disorders with Asymptomatic Subjects

Watanabe K., Daimon K., Fujiwara H., Nishiwaki Y., Okada E., Nojiri K., Watanabe M., Katoh H., Shimizu K., Ishihama H., Fujita N., Ichihara D., Tsuji T., Nakamura M., Matsumoto M.

Spine (Spine) 46 ( 11 ) 710 - 716 2021.06

STUDY DESIGN: A longitudinal, 20-year comparative study of patients with whiplash-associated disorders (WAD). OBJECTIVE: The aim of this study was to clarify the long-term impact of WAD on patient symptoms and on magnetic resonance imaging (MRI) findings of the cervical spine, in comparison with asymptomatic volunteers. SUMMARY OF BACKGROUND DATA: The long-term impact of WAD has not been fully elucidated. METHODS: Between 1993 and 1996, we conducted a cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers, all of whom underwent MRI on cervical spine and physical examinations. For this 20-year follow-up comparative study, 75 WAD patients and 181 control subjects aged <60 years were recruited from the original cohort. The MRI findings, including discs' signal intensities, posterior disc protrusions, anterior dural compressions, spinal cord disc space narrowing, and foraminal stenoses, were evaluated using two to four numerical grades. The results of the WAD patients and control subjects were compared. RESULTS: In this follow-up, the prevalence of shoulder stiffness (72.0% vs. 45.9%), headache (24.0% vs. 12.2%), and arm pain (13.3% vs. 3.9%) were significantly greater in WAD patients than in control subjects. The multiregression analysis revealed that a history of WAD was associated with shoulder stiffness (odds ratio [OR]: 3.36), headache (OR: 2.39), and arm pain (OR: 3.82). Although MRI findings in WAD patients were more degenerated than in control subjects in the initial study, all MRI findings were similar at the 20-year follow-up. There were no significant correlations between clinical cervical symptoms and progression in each MR finding in either group. CONCLUSION: After 20 years, whiplash injuries significantly impacted the residual symptoms of shoulder stiffness, headache, and arm pain when compared with initially asymptomatic volunteers. The progression of degenerative changes in the cervical intervertebral discs after 20 years revealed no association with existing whiplash injuries, neither did the residual cervical-related symptoms.Level of Evidence: 3.

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Baseline severity of myelopathy predicts neurological outcomes after posterior decompression surgery for cervical spondylotic myelopathy: a retrospective study

Nori S., Nagoshi N., Kono H., Kobayashi Y., Isogai N., Ninomiya K., Tsuji T., Horiuchi Y., Takemura R., Kimura R., Tsuji O., Suzuki S., Okada E., Yagi M., Nakamura M., Matsumoto M., Watanabe K., Ishii K., Yamane J.

Spinal Cord (Spinal Cord) 59 ( 5 ) 547 - 553 2021.05

ISSN 13624393

Study design: Retrospective multicenter study. Objectives: To identify the usefulness of the baseline severity of myelopathy for predicting surgical outcomes for cervical spondylotic myelopathy (CSM). Setting: Seventeen institutions in Japan. Methods: This study included 675 persons with CSM who underwent posterior decompression. According to baseline severity, the individuals were divided into the mild (Japanese Orthopaedic Association [JOA] score ≥ 14.5), moderate (JOA score = 10.5–14), and severe (JOA score ≤ 10) groups. Surgical outcomes and clinical variables were compared between the groups. Logistic regression analysis was used to develop a prediction model for unsatisfactory symptom state (postoperative JOA score ≤ 14, residual moderate or severe myelopathy). Results: The mean (±standard deviation) age was 67 ± 12 years. The participants in the severe group were older than those in the mild group. Postoperative JOA scores were higher in the mild group than in the severe group. According to multivariate logistic regression analysis, the prediction model included preoperative JOA scores (odds ratio [OR] 0.60; 95% confidence interval [CI] 0.55–0.67) and age (OR 1.06, 95% CI 1.04–1.08). On the basis of the model, a representative combination of the thresholds to maximize the value of “sensitivity − (1 − specificity)” demonstrated a preoperative JOA score of 11.5 as a predictor of postoperative unsatisfactory symptom state in people around the mean age of the study cohort (67 years). Conclusions: The combination of the baseline severity of myelopathy and age can predict postoperative symptom states after posterior decompression surgery for CSM.

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Predictors of neurologic outcome after surgery for cervical ossification of the posterior longitudinal ligament differ based on myelopathy severity: A multicenter study

Shin J.J., Jeon H., Lee J.J., Kim H.C., Kim T.W., An S.B., Shin D.A., Yi S., Kim K.N., Yoon D.H., Nagoshi N., Watanabe K., Nakamura M., Matsumoto M., Li N., Ma S., He D., Tian W., Kwan K.Y.H., Cheung K.M.C., Riew K.D., Hoh D.J., Ha Y.

Journal of Neurosurgery: Spine (Journal of Neurosurgery: Spine) 34 ( 5 ) 749 - 758 2021.05

ISSN 15475654

OBJECTIVE The purpose of this retrospective multicenter study was to compare prognostic factors for neurological recovery in patients undergoing surgery for cervical ossification of the posterior longitudinal ligament (OPLL) based on their presenting mild, moderate, or severe myelopathy. METHODS The study included 372 consecutive patients with OPLL who underwent surgery for cervical myelopathy between 2006 and 2016 in East Asian countries with a high OPLL prevalence. Baseline and postoperative clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) myelopathy score and recovery ratio. Radiographic assessment included occupying ratio, cervical range of motion, and sagittal alignment parameters. Patient myelopathy was classified as mild, moderate, or severe based on the preoperative JOA score. Linear and multivariate regression analyses were performed to identify patient and surgical factors associated with neurological recovery stratified by baseline myelopathy severity. RESULTS The mean follow-up period was 45.4 months (range 25-140 months). The mean preoperative and postoperative JOA scores and recovery ratios for the total cohort were 11.7 ± 3.0, 14.5 ± 2.7, and 55.2% ± 39.3%, respectively. In patients with mild myelopathy, only age and diabetes correlated with recovery. In patients with moderate to severe myelopathy, older age and preoperative increased signal intensity on T2-weighted imaging were significantly correlated with a lower likelihood of recovery, while female sex and anterior decompression with fusion (ADF) were associated with better recovery. CONCLUSIONS Various patient and surgical factors are correlated with likelihood of neurological recovery after surgical treatment for cervical OPLL, depending on the severity of presenting myelopathy. Older age, male sex, intramedullary high signal intensity, and posterior decompression are associated with less myelopathy improvement in patients with predomiworse baseline function. Therefore, myelopathy-specific preoperative counseling regarding prognosis for postoperative long-term neurological improvement should include consideration of these individual and surgical factors.

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Residual lumbar curvature that developed during adolescence accelerates intervertebral disc degeneration in adulthood

Suzuki S., Fujiwara H., Nori S., Tsuji O., Nagoshi N., Okada E., Fujita N., Yagi M., Nohara A., Kawakami N., Michikawa T., Nakamura M., Matsumoto M., Watanabe K.

Spine Deformity (Spine Deformity) 9 ( 3 ) 711 - 720 2021.05

ISSN 2212134X

Purpose: To elucidate the influence of spinal deformity in adolescent idiopathic scoliosis (AIS) on lumbar intervertebral disc (IVD) degeneration in adulthood using magnetic resonance imaging (MRI). Methods: A total of 102 patients (8 men, 94 women; mean age, 31.4 years) who had developed idiopathic scoliosis at the age of 10–18 years and underwent preoperative lumbar spine MRI at the age of ≥ 20 were included in the study. Twenty volunteers (3 men, 17 women; mean age, 33.6 years) without scoliosis were assessed as controls. We divided the adult scoliosis patients into two groups: Group A consisted of patients with lumbar modifier A, and Group BC consisted of those with modifiers B and C. IVD degeneration from L1/2 to L5/S1 was assessed by MRI. The Scoliosis Research Society-22 (SRS-22) patient questionnaire was used in the patients’ clinical assessment. Results: There were 40 patients in the Group A and 62 in the Group BC. Compared to the control groups, significant IVD degeneration was observed at L2/3 and L3/4 in Group A, and at all levels except for L5/S1 in Group BC. The proportion of degenerated IVDs patients (Grades 1c and 2) was significantly higher in Group BC than those in Group A at L3/L4 and L4/L5. Furthermore, the severity of IVD degeneration was significantly greater in the group BC than in the group A at all levels, except for L5/S1, especially in patients aged > 30 years. The mean scores of all subdomains in the SRS-22 questionnaire were comparable between the two groups. Conclusion: Our study showed that the residual lumbar curvature from AIS may have accelerated IVD degeneration in adulthood, especially in patients aged > 30 years. Level of evidence: III.

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Incidence and Risk Factors for Unplanned Return to the Operating Room Following Primary Definitive Fusion for Pediatric Spinal Deformity: A Multicenter Study with Minimum 2-year Follow-Up

Taniguchi Y., Ohara T., Suzuki S., Watanabe K., Suzuki T., Uno K., Yamaguchi T., Yanagida H., Nakayama K., Kotani T., Watanabe K., Hirano T., Yamamoto T., Kawamura I., Sugawara R., Takeshita K., Demura S., Oku N., Sato T., Fujiwara K., Akazawa T., Murakami H., Kakutani K., Matsubayashi Y., Kawakami N.

Spine (Spine) 46 ( 8 ) E498 - E504 2021.04

STUDY DESIGN: A retrospective multicenter cohort study. OBJECTIVE: The aim of this study was to identify the incidence and risk factors for UPROR within minimum 2-year follow-up in primary definitive fusion for pediatric spinal deformity. SUMMARY OF BACKGROUND DATA: Several previous reports have elucidated the incidence of complications after pediatric scoliosis surgery; however, there has been no study that described the incidence and risk factors for unplanned return to the operating room (UPROR) with long-term follow-up in surgery for pediatric scoliosis with every etiology. METHODS: We retrospectively extracted data of patients aged <19 years, from 14 institutes in Japan, who underwent primary definitive fusion surgery for spinal deformity between January 1, 2015 and December 31, 2017. The primary outcomes were the incidence of UPROR within the minimum 2-year follow-up period for any reason. Univariate and multivariate logistical analyses were conducted to identify potential risk factors associated with UPROR. RESULTS: We identified 1417 eligible patients (287 males and 1130 females) with a mean age of 13.9 years. UPROR for any reason within minimum 2-year follow-up was identified in 68 patients (4.8%). The most frequent cause for UPROR was implant failure found in 29 patients, followed by surgical site infection in 14 patients, junctional problems in 10 patients, and neurological complications in six patients. The multivariate logistic regression analysis revealed that a diagnosis of kyphosis (odds ratio [OR], 2.65; 95% confidence interval [CI] 1.16-6.04), etiology of congenital or structural type (OR 2.21; 95% CI 1.08-4.53), etiology of syndromic type (OR 2.67; 95% CI 1.27-5.64), and increased operation time of ≥300 minutes (OR 1.81; 95% CI 1.07-3.07) were the risk factors for the incidence of UPROR. CONCLUSION: The present multicenter study identified for the first time the incidence and risk factors for UPROR with minimum 2-year follow-up after primary definitive fusion surgery for pediatric spinal deformity with every etiology.Level of Evidence: 3.

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Diabetes Does Not Adversely Affect Neurological Recovery and Reduction of Neck Pain After Posterior Decompression Surgery for Cervical Spondylotic Myelopathy: Results From a Retrospective Multicenter Study of 675 Patients

Nori S., Nagoshi N., Yoshioka K., Nojiri K., Takahashi Y., Fukuda K., Ikegami T., Yoshida H., Iga T., Tsuji O., Suzuki S., Okada E., Yagi M., Nakamura M., Matsumoto M., Watanabe K., Ishii K., Yamane J.

Spine (Spine) 46 ( 7 ) 433 - 439 2021.04

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: The aim of this study was to identify the impact of diabetes on surgical outcomes of posterior decompression for cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Although some previous studies have reported surgical outcomes of posterior decompression for CSM in diabetic patients, their results were inconsistent. METHODS: We included 675 patients with CSM who underwent posterior decompression. Patients were divided into diabetic (n = 140) and nondiabetic (n = 535) groups according to the diabetic criteria for glucose intolerance. Surgical outcomes as assessed by the Japanese Orthopedic Association (JOA) scores and visual analog scale (VAS) for neck pain were compared between groups. Subsequently, the functional outcomes of diabetic patients were compared between the mild (n = 131) and moderately severe (n = 9) groups. All patients were followed up for at least 1 year after surgery. RESULTS: Compared with the nondiabetic group, the diabetic group showed lower pre- and postoperative JOA scores (P = 0.025 and P = 0.001, respectively) and a lower JOA score recovery rate (RR) (P = 0.009). However, the preoperative-to-postoperative changes in JOA scores in the diabetic and nondiabetic groups were not significantly different (P = 0.988). Pre- and postoperative VAS for neck pain and postoperative reduction of neck pain were comparable between groups (P = 0.976, P = 0.913 and P = 0.688, respectively). Although statistical analysis was not performed due to the small underpowered sample size, functional outcomes assessed by the JOA score RR (43.3 ± 37.1% vs. 45.3 ± 33.9%) and preoperative-to-postoperative changes in JOA scores (3.0 ± 2.2 vs. 2.7 ± 2.5) were similar between the mild and moderately severe diabetes groups. CONCLUSION: CSM patients with diabetes experienced improvements in neurological function and neck pain as a result of posterior decompression to the same extent seen in patients without diabetes.Level of Evidence: 3.

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Posterior and Anterior Fusion for Severe Cervical Kyphosis in a Patient with Chondrodysplasia Punctata: A Case Report

Kato S., Fujita N., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

JBJS case connector (JBJS case connector) 11 ( 1 ) 2021.03

CASE: A 4-year-old girl with spastic gait and hand clumsiness who was diagnosed with cervical myelopathy caused by atlantoaxial dislocation and midcervical severe kyphosis associated with chondrodysplasia punctata (CDP). The patient underwent posterior instrumentation and anterior spinal fusion and successful correction with osseous fusion was obtained 8 months after surgery. In addition, the preoperative neurological symptoms were completely recovered. CONCLUSION: Owing to the characteristics of CDP, the treatment for the cervical lesion is extremely complicated. Successful stabilization and improvement of the neurological symptom were achieved by combining posterior and anterior fusion with instrumentation in this case.

Gorham-Stout Disease Resulting in Spinal Deformity Treated by Fusion Surgery Combined With Everolimus Therapy: A Case Report

Toga A., Watanabe K., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Yagi M., Fujita N., Nakamura M., Matsumoto M.

JBJS case connector (JBJS case connector) 11 ( 1 ) 2021.03

CASE: Gorham-Stout disease (GSD) is a rare disorder characterized by progressive localized osteolysis and lymphatic malformation. A 26-year-old woman with GSD presented to our hospital with a Cobb angle of 100° and a kyphosis angle of 88°. Everolimus therapy was initiated to control the disease prior to surgery. After halo-gravity traction for 4 weeks, we performed anterior and posterior spinal fusion. Postoperative computed tomography revealed satisfactory bone union and no significant loss of correction 1 year post-surgery. CONCLUSION: This case suggests that anterior and posterior spinal fusion combined with everolimus therapy can be a therapeutic option for GSD.

Symptomatic postoperative spinal subdural hematoma following posterior lumbar spinous process-splitting decompression surgery for lumbar spinal canal stenosis: A case report

Ito K., Fujita N., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

Spine Surgery and Related Research (Spine Surgery and Related Research) 5 ( 5 ) 117 - 119 2021.03

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Proximal junctional kyphosis and proximal junctional failure in the treatment for adult spinal deformity: Definitions and epidemiology

Watanabe K., Yagi M., Fujita N., Suzuki S., Tsuji O., Nagoshi N., Okada E., Nakamura M., Matumoto M.

Techniques in Orthopaedics (Techniques in Orthopaedics) 36 ( 1 ) 2 - 6 2021.03

ISSN 08859698

Proximal junctional failure (PJF) is considered to be one of the most serious complications after correction surgery with a long construct for adult spinal deformity. Proximal junctional kyphosis (PJK) was first defined as an angle between the lower endplate of the uppermost instrumented vertebra (UIV) and the upper endplate of UIV+2 of 10 degrees or greater, and at least 10 degrees greater than the preoperative measurement. Although PJK has been found to cause no significant clinical symptoms, PJF is regarded as a pathology associated with a fracture of UIV or UIV+1, posterior osseoligamentous disruption, or a pullout of instrumentation at the UIV, and may require revision surgery. The incidence of PJK or PJF is influenced by a variety of factors including the pathology of the deformity, surgical procedures and spinal construct, status of osteoporosis, prophylactic procedures, and the follow-up period. Therefore, the reported incidences of PJK vary widely, from 7.7% to 56%, whereas those of PJF vary widely, from 1.4% to 35%.

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Predictive Probability of the Global Alignment and Proportion Score for the Development of Mechanical Failure Following Adult Spinal Deformity Surgery in Asian Patients

Yagi M., Daimon K., Hosogane N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 46 ( 2 ) E80 - E86 2021.01

STUDY DESIGN: This is a multicenter retrospective review of 257 surgically treated consecutive ASD patients who had a minimum of five fused segments, completed a 2-year follow-up (53 ± 19 yrs, females: 236 [92%]). OBJECTIVE: This study aimed to validate the predictive probability of the GAP score in an Asian ASD patient cohort. SUMMARY OF BACKGROUND DATA: The GAP score is a recently established risk stratification model for MF following ASD surgery. However, the predictive ability of the GAP score is not well studied. This study aimed to validate the predictive probability of the GAP score in an Asian ASD patient cohort. METHODS: Comparisons of the immediate postoperative GAP scores between MF the and MF-free groups were performed. We evaluated the discriminative ability of the GAP score based on the area under the receiver operating characteristic curve (AUROC). The Cuzick test was performed to determine whether there is a trend between the GAP score and the incidence of MF or revision surgery. Univariate logistic regression analyses were performed to explore the associations between the GAP score and the incidence of MF or revision surgery. RESULTS: No difference was observed in the GAP score between the MF and MF-free groups (MF vs. MF-free; GAP: 5.9 ± 3.3 vs. 5.2 ± 2.7, P = 0.07). The Cuzick analysis showed no trend between the GAP score and the risk for MF or revision surgery. Likewise, the MF rate was not correlated with the GAP score, as shown by the ROC curve (AUC of 0.56 [95% CI 0.48-0.63], P = 0.124). Univariate logistic regression confirmed no associations between the GAP score and the incidence of MF or revision surgery (MF; moderately disproportioned [MD]: OR: 0.6 [95% CI: 0.3-1.2], P = 0.17, severely disproportioned [SD]: OR: 1.2 [95% CI: 0.6-2.3], P = 0.69, revision surgery; MD: OR: 0.8 [95% CI: 0.2-2.8], P = 0.71, SD: OR: 1.2 [95% CI: 0.9-8.7], P = 0.08). CONCLUSION: In this multicenter study, in an Asian ASD patient cohort, the GAP score was not associated with the incidence of MF or revision surgery. Additional studies on the predictive ability of the GAP score in different patient cohorts are warranted.Level of Evidence: 3.

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Limited cost benefit of lateral interbody fusion for adult spinal deformity surgery

Yamamoto T., Yagi M., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 46 ( 1 ) 48 - 53 2021.01

ISSN 03622436

Study Design. Retrospective case series. Objective. The aim of this study was to compare the utility and cost-effectiveness of multilevel lateral interbody fusion (LIF) combined with posterior spinal fusion (PSF) (L group) and conventional PSF (with transforaminal lumbar interbody fusion) (P group) in adult spinal deformity (ASD) surgery. Summary of Background Data. The clinical and radiographic outcomes of multilevel LIF for ASD have been reported favorable; however, the cost benefit of LIF in conjunction with PSF is still controversial. Methods. Retrospective comparisons of 88 surgically treated ASD patients with minimum 2-year follow-up from a multicenter database (L group [n=39] and P group [n=49]) were performed. Demographic and radiographic data, health-related quality of life (HRQoL), and the direct hospitalization cost for the initial surgery and 2-year total hospitalization cost were analyzed. Results. Analyses of sagittal spinal alignment showed no significant difference between the two groups at baseline and 2 years post-operation. Surgical time was longer in the L group (L vs. P: 354 vs. 268 minutes, P<0.01), whereas the amount of blood loss was greater in the P group (494 vs. 678 mL, P=0.03). The HRQoL was improved similarly at 2 years post-operation (L vs. P: SRS-22 total score, 3.86 vs. 3.80, P=0.54), with comparable revision rates (L vs. P: 18% vs. 10%, P=0.29). The total direct cost of index surgery was significantly higher in the L group (65,937 vs. 49,849 USD, P<0.01), which was mainly due to the operating room cost, including implant cost (54,466 vs. 41,328 USD, P<0.01). In addition, the 2-year total hospitalization cost, including revision surgery, was also significantly higher in the L group (70,847 vs. 52,560 USD, P<0.01). Conclusion. LIF with PSF is a similarly effective surgery for ASD when compared with conventional PSF. However, due to the significantly higher cost, additional studies on the costeffectiveness of LIF in different ASD patient cohorts are warranted.

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K-line (−) in the neck-flexed position negatively affects surgical outcome of expansive open-door laminoplasty for cervical spondylotic myelopathy

Nori S., Nagoshi N., Suzuki S., Tsuji O., Okada E., Yagi M., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

Background: The K-line in the neck-flexed position (FK-line) on radiography reflects dynamic factors and cervical alignment. Although the FK-line has been reported to affect the neurological recovery after muscle-preserving selective laminectomy for cervical spondylotic myelopathy (CSM), its influence on surgical outcomes after expansive open-door laminoplasty (ELAP) has not been investigated. Methods: We reviewed the surgical outcomes in 81 patients with multilevel CSM who underwent C4–C6 ELAP combined with C3 and C7 partial laminectomy using a laminoplasty plate and were followed up for at least 2 years. We defined the K-line (−) as some portion of a bony spur or the vertebral body crossing the FK-line, whereas the FK-line (+) was defined as that never crossing the FK-line. Patients were divided into the FK-line (+) (n = 61) and FK-line (−) groups (n = 20), and the surgical outcomes were compared between the groups. A multivariate analysis was performed to identify the factors that influenced the neurological outcomes. Results: The FK-line (−) group had a smaller C2–C7 angle, smaller C7 slope, greater postoperative increase in the C2–C7 sagittal vertical axis, greater kyphosis in cervical flexion and less lordosis in cervical extension, and higher incidence of postoperative residual spinal cord compression. The preoperative-to-postoperative changes in the Japanese Orthopedic Association (JOA) score and JOA score recovery rate (RR) were lower in the FK-line (−) group. The multiple linear regression analysis revealed that the K-line (−) (β = −0.327, P = 0.011) and high signal intensity (SI) changes on T2-weighted imaging (WI) combined with the low SI changes on T1-WI in the spinal cord (β = −0.320, P = 0.013) negatively affected the JOA score RR. Conclusions: The FK-line can be used for patients with CSM as a simple indicator of neurological outcomes after ELAP.

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Imaging Characteristics and Surgical Outcomes in Patients With Intraspinal Solitary Fibrous Tumor/Hemangiopericytoma: A Retrospective Cohort Study

Okubo T., Nagoshi N., Tsuji O., Tachibana A., Kono H., Suzuki S., Okada E., Fujita N., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Global Spine Journal (Global Spine Journal) 2021

ISSN 21925682

Study Design: Retrospective cohort study. Objectives: Intraspinal solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is often misdiagnosed preoperatively as schwannoma or meningioma because its imaging characteristics are not well understood. As postoperative prognosis differs among the 3 lesions, predicting the probability of SFT/HPC preoperatively is essential. Thus, this study investigates the imaging characteristics of SFT/HPC compared with those of schwannoma or meningioma and evaluates surgical outcomes. Methods: The preoperative imaging findings, tumor resection extent, recurrence and regrowth rates, and neurological improvement were compared between 10 patients with SFT/HPC and 42 patients with schwannoma or 40 patients with meningioma. Results: Most patients with SFT/HPC showed isointensity on both T1- and T2-weighted images compared with patients with schwannoma (P = 0.011 and 0.029, respectively) and no significant difference compared with patients with meningioma (P = 0.575 and 0.845, respectively). Almost all patients with SFT/HPC showed highly uniformizing enhancement patterns, similar to those with meningioma (P = 0.496). Compared with meningioma, SFT/HPC lacked the dural tail sign and intratumoral calcification and exhibited irregular shape. Of the 5 patients who underwent partial resection, 60% exhibited tumor recurrence and regrowth following surgery. Conclusions: Complete en bloc surgical resection should be attempted in patients with intraspinal SFT/HPC to prevent postoperative recurrence or regrowth. As this tumor is often preoperatively misdiagnosed, we recommend that the imaging findings exhibited in this study should be used to positively suspect SFT/HPC. This will enhance patient outcomes by enabling more appropriate preoperative surgical planning.

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Effectiveness of Duloxetine for Postsurgical Chronic Neuropathic Disorders after Spine and Spinal Cord Surgery

Tsuji O., Kosugi S., Suzuki S., Nori S., Nagoshi N., Okada E., Fujita N., Yagi M., Nakamura M., Matsumoto M., Watanabe K.

Asian Spine Journal (Asian Spine Journal) 15 ( 5 ) 650 - 658 2021

ISSN 19761902

Study Design: This is a retrospective observational study with an outpatient setting.Purpose: This study aimed to describe the effects of duloxetine (DLX) administration for postsurgical chronic neuropathic disorders(both pain and numbness) following spinal surgery in patients without depression.Overview of Literature: Although several reports indicated the potential of DLX to effectively treat postoperative symptoms as aperioperative intervention, there have been no reports of its positive effect on postsurgical chronic neuropathic disorders.Methods: A total of 24 patients with postsurgical chronic pain and/or numbness Numeric Rating Scale (NRS) scores of ≥4 wereenrolled. All patients underwent spine or spinal cord surgery at Keio University Hospital and received daily administration of DLX formore than 3 months. The mean postoperative period before the first administration of DLX was 35.5±57.0 months. DLX was administeredfor more than 3 months at a dose of 20, 40, or 60 mg/day, and the degree of pain and numbness was evaluated using the NRSbefore administration and 3 months after administration. Effectiveness was defined as more than a 2-point decrease in the NRS scorefollowing administration.Results: In terms of the type of symptoms, 15 patients experienced only numbness, eight experienced both pain and numbness, andone experienced only pain. Of the 24 patients, 19 achieved effective relief with DLX. DLX was effective for all patients with postsurgicalchronic pain (n=9), and it reduced postsurgical chronic numbness in 18 of 23 patients. No significant difference was observed inbackground spinal disorders. DLX was not effective for five patients who complained only of postsurgical chronic numbness.Conclusions: This study reports the effectiveness of DLX for postsurgical chronic neuropathic disorders. Although DLX reduced postsurgicalchronic pain (efficacy rate=100%) and numbness (78.3%) in certain patients, further investigation is needed to determine itsoptimal use

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Early-onset scoliosis associated with shprintzen-goldberg syndrome treated with growing rods and required multiple unplanned surgeries: A case report

Takahashi Y., Watanabe K., Yagi M., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Fujit N., Nakamura M., Matsumoto M.

Spine Surgery and Related Research (Spine Surgery and Related Research) 5 ( 3 ) 214 - 217 2021

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Does Diabetes Affect the Surgical Outcomes in Cases With Cervical Ossification of the Posterior Longitudinal Ligament? A Multicenter Study From Asia Pacific Spine Study Group

Nagoshi N., Watanabe K., Nakamura M., Matsumoto M., Li N., Ma S., He D., Tian W., Jeon H., Lee J.J., Kim K.N., Ha Y., Hong Kwan K.Y., Po Cheung A.K.

Global Spine Journal (Global Spine Journal) 2021

ISSN 21925682

Study Design: Retrospective multicenter study. Objectives: To evaluate the surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL) in diabetes mellitus (DM) patients. Methods: Approximately 253 cervical OPLL patients who underwent surgical decompression with or without fixation were registered at 4 institutions in 3 Asian countries. They were followed up for at least 2 years. Demographics, imaging, and surgical information were collected, and cervical Japanese Orthopaedic Association (JOA) scores and the visual analog scale (VAS) for the neck were used for evaluation. Results: Forty-seven patients had DM, showing higher hypertension and cardiovascular disease prevalence. Although they presented worse preoperative JOA scores than non-DM patients (10.5 ± 3.1 vs. 11.8 ± 3.2; P = 0.01), the former showed comparable neurologic recovery at the final follow-up (13.9 ± 2.9 vs. 14.2 ± 2.6; P = 0.41). No correlation was noted between the hemoglobin A1c level in the DM group and the pre- and postoperative JOA scores. No significant difference was noted in VAS scores between the groups at pre- and postsurgery. Regarding perioperative complications, DM patients presented a higher C5 palsy frequency (14.9% vs. 5.8%; P = 0.04). A similar trend was observed when surgical procedure was limited to laminoplasty. Conclusions: This is the first multicenter Asian study to evaluate the impact of DM on cervical OPLL patients. Surgical results were favorable even in DM cases, regardless of preoperative hemoglobin A1c levels or operative procedures. However, caution is warranted for the occurrence of C5 palsy after surgery.

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Comparable satisfaction and clinical outcomes after surgery for adolescent idiopathic scoliosis in the adult (AISA) between the US and Japan

Yagi M., Ames C.P., Hosogane N., Smith J.S., Shaffrey C.I., Schwab F.J., Lafage V., Bess S., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

Background: The impact of ethnicity on the surgery outcomes of adolescent idiopathic scoliosis in the adult (AISA) is poorly understood. This study aimed to compare the surgery outcomes for AISA between the United States (US) and Japan (JP). Methods: 171 surgically treated AISA (20-40y) were consecutively collected from 2 separate multicenter databases. Patients were propensity-score matched for age, gender, curve type, levels fused, and 2y postop spinal alignment. Demographic and radiographic parameters were compared between the US and JP at baseline and 2y post-op. Results: A total of 108 patients were matched by propensity score (age; US vs. JP: 29 ± 6 vs. 29 ± 7y, females: 76 vs. 76%, curve type [Schwab-SRS TypeT; TypeD; TypeL; TypeN]: 35; 35; 30; 0 vs. 37; 33; 30; 0%)] levels fused: 10 ± 4 vs. 10 ± 4, 2y thoracic curve:17 ± 13 vs. 17 ± 12°, 2y CSVL: 10 ± 8 vs. 11 ± 9 mm). Similar clinical improvement was achieved between US and JP (function; 4.2 ± 0.9 vs 4.3 ± 0.6, p = 0.60, pain; 3.8 ± 0.9 vs 4.1 ± 0.8, p = 0.13, satisfaction; 4.3 ± 0.9 vs 4.2 ± 0.7, p = 0.61, total; 4.0 ± 0.8 vs 4.1 ± 0.5, p = 0.60). The correlation analyzes indicated that postoperative SRS-22 subdomains correlated differently with satisfaction (all subdomains moderately correlated with satisfaction in the US while only pain and mental health correlated moderately with satisfaction in JP ([function: r = 0.61 vs 0.29, pain: r =. 72 vs 0.54, self-image: r = 0.72 vs 0.37, mental health: r = 0.64 vs 0.55]). Conclusions: Surgery for AISA was similarly effective in the US and JP. Satisfaction for spinal surgery among patients in different countries may not be different unless the procedure limits an individual's unique lifestyle that the patient expected to resume.

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A rare case of dumbbell-shaped lymphoplasmacyte-rich meningioma arising at the upper cervical spinal cord

Fukui K., Tsuji O., Suzuki S., Nori S., Nagoshi N., Okada E., Yagi M., Okita H., Fujita N., Watanabe K., Nakamura M., Matsumoto M.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

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The characteristics of the young patients with cervical ossification of the posterior longitudinal ligament of the spine: A multicenter cross-sectional study

Mori K., Yoshii T., Hirai T., Maki S., Katsumi K., Nagoshi N., Nishimura S., Takeuchi K., Ushio S., Furuya T., Watanabe K., Nishida N., Watanabe K., Kaito T., Kato S., Nagashima K., Koda M., Ito K., Imagama S., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Watanabe M., Matsumoto M., Nakamura M., Yamazaki M., Okawa A., Kawaguchi Y.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

Background: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. Although the patients with OPLL are more common in the 60s and 70s, we know that there are markedly young patients (e.g., early 40s). However, to the best of our knowledge, there is few reports characterize young patients with cervical OPLL in terms of the imaging features, subjective symptoms, and ADL problems. Methods: This is the multicenter cross-sectional study. Two hundred and thirty-seven Japanese symptomatic patients with cervical OPLL confirmed by standard X-rays collected from 16 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament formed by the Japanese Ministry of Health, Labor and Welfare were recruited. Whole spine CT data as well as demographic data such as age, gender, patients-based evaluations, and the 36-item Short Form Health Survey (SF-36) were evaluated. Results: Young group (≦ 45 years old) consisted of 23 patients (8 females and 15 males), accounting for 9.7% of the total. Their characteristics were high body mass index (BMI), significant involvement of trauma in the onset and deterioration of symptoms, and the predominance of thoracic OPLL. The patient-based evaluations did not show a significant difference between the young and non-young groups, or between the genders in the young group except for bodily pain (BP) of SF-36. Female patients in young group had significantly lower BP score of SF-36 than that of male in young group. Conclusions: Characteristics of young patients with cervical OPLL were high BMI, significant involvement of trauma in the onset and deterioration of symptoms, lower BP score of SF-36 in female, and the predominance of thoracic OPLL.

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The impact of diabetes mellitus on spinal fracture with diffuse idiopathic skeletal hyperostosis: A multicenter retrospective study

Yamamoto T., Okada E., Michikawa T., Yoshii T., Yamada T., Watanabe K., Katsumi K., Hiyama A., Watanabe M., Nakagawa Y., Okada M., Endo T., Shiraishi Y., Takeuchi K., Matsunaga S., Maruo K., Sakai K., Kobayashi S., Ohba T., Wada K., Ohya J., Mori K., Tsushima M., Nishimura H., Tsuji T., Koda M., Okawa A., Yamazaki M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

Background: Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH. Methods: We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups. Results: DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference. Conclusions: In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.

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Upper End Vertebra of Proximal Thoracic Curve At T1 is a Novel Risk Factor of Postoperative Shoulder Imbalance in Lenke Type 2 Adolescent Idiopathic Scoliosis

Isogai N., Yagi M., Otomo N., Maeda Y., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Global Spine Journal (Global Spine Journal) 2021

ISSN 21925682

Study Design: Retrospective single-center study. Objective: We investigated the risk factors of postoperative shoulder imbalance (PSI) in patients with Lenke type 2 adolescent idiopathic scoliosis (AIS) including the position of preoperative upper end vertebra (UEV). Methods: Seventy-five patients with Lenke type 2 AIS who underwent posterior correction and fusion surgeries from 2008 to 2018 were included. We included only patients whose upper instrumented vertebrae were at T2. The patients were divided into 2 groups based on radiographic shoulder height (RSH) at final follow-up, namely PSI group and non-PSI group, and PSI was defined as RSH > 10 mm. UEV, RSH, Cobb angle, curve flexibility, T1 and T2 tilt, correction rate, Risser grade, Scoliosis Research Society-22 scores, and demographic data were compared between the groups using independent t-tests or chi-square tests. Variables with P value < 0.20 in univariate analysis were assessed in logistic regression analysis. Results: Thirty-four patients in the PSI group and 37 patients in the non-PSI group were analyzed. Univariate analysis revealed that there were more patients with UEV at T1 (PSI: 85%, non-PSI: 54%, P < 0.01) and Risser grade ≥ 3 (PSI: 88%, non-PSI: 62%; P < 0.05) in the PSI group than in the non-PSI group. Logistic regression analysis revealed that UEV at T1 (odds ratio [OR] = 4.1 [1.2–14.4], P < 0.05) and Risser grade ≥ 3 (OR = 3.9 [1.1–14.5], P < 0.05) are significantly associated with PSI. Conclusions: UEV at T1 and Risser grade ≥ 3 at the time of surgery are significant risk factors of PSI.

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Metabolic syndrome is a predisposing factor for diffuse idiopathic skeletal hyperostosis

Okada E., Ishihara S., Azuma K., Michikawa T., Suzuki S., Tsuji O., Nori S., Nagoshi N., Yagi M., Takayama M., Tsuji T., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Neurospine (Neurospine) 18 ( 1 ) 109 - 116 2021

ISSN 25866583

Objective: Diffuse idiopathic skeletal hyperostosis (DISH) causes spinal ankylosis, which can result in patients suffering specific spinal fractures that lead to a reduction in the activities of daily life in older patients. Currently, DISH is associated with diabetes mellitus and cardiovascular disease; however, the association between DISH and metabolic syndrome has not been established. The purpose of this study was to investigate a potential association between DISH and metabolic syndrome. Methods: We retrospectively reviewed clinical data from consecutive subjects undergoing the musculoskeletal health medical checkups, and enrolled 327 subjects (174 men and 153 women; mean, 63.4 ± 13.7-years). Subjects who had spinal ankylosis at least 4 contiguous vertebral bodies were classified as the DISH group (n = 39) while the others were part of the non-DISH group (n = 288). The definition of the metabolic syndrome comes from diagnostic criteria used by the Japanese Society for Internal Medicine. Age, sex, body max index (BMI), hematological evaluation, blood pressure, presence of metabolic syndrome, the visceral fat area on abdominal computed tomography, and spinal epidural lipomatosis (SEL) on magnetic resonance imaging were evaluated. Results: Compared to the non-DISH group, in the DISH group, mean age (DISH group, 74.3 years; non-DISH group, 1.9 years; p < 0.001), male prevalence were higher (DISH group, 82.1%; non-DISH group, 49.3%; p < 0.001), and BMI was greater (DISH group, 24.8; non-DISH group, 23.0; p = 0.006). the metabolic syndrome was more frequently observed in DISH group (28.9%) than in the non-DISH group (16.0%) (p = 0.045). The visceral fat area was significantly larger in the DISH group than in the non-DISH group (DISH group, 130.7 ± 58.2 cm2; Non-DISH group, 89.0 ± 48.1 cm2; p <0.001). The prevalence of SEL was similar between the 2 groups (10.3% in the DISH group vs. 8.7% in the non-DISH group; p = 0.464). Poisson regression analysis revealed that the metabolic syndrome was significantly associated with DISH with odds ratio of 2.0 (95% confidence interval, 1.0– 3.7; p = 0.004). Conclusion: Metabolic syndrome was significantly associated with DISH. Our data showed metabolic syndrome is potentially related to DISH.

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Spinous Process-Splitting Laminectomy Approach for Tumor Excision at Conus Medullaris or Cauda Equina Level Results in Satisfactory Clinical Outcomes Without Affecting Global Spinal Sagittal Alignment

Okubo T., Nagoshi N., Tsuji O., Nishimura S., Suzuki S., Nori S., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Global Spine Journal (Global Spine Journal) 2021

ISSN 21925682

Study design: Retrospective comparative study. Objectives: The present study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes following tumor resection using spinous process-splitting laminectomy (SPSL) approach without fixation in patients with conus medullaris (CM) or cauda equina (CE) tumor. Methods: Forty-one patients with CM or CE tumor (19 males, 22 females, mean age at surgery of 52.9 ± 13.0 years) were included in this study. The variations of outcome variables were analyzed in various GSSA profiles using radiographic outcomes. The clinical outcomes were assessed using Japan Orthopaedic Association (JOA) score and JOA back pain evaluation questionnaire (JOABPEQ). Results: In all cases, the various GSSA parameters (sagittal vertical axis, C2–7 lordosis, T1 slope, thoracic kyphosis, T10–L2 kyphosis, lumbar lordosis [LL; upper, middle, and lower], sacral slope, pelvic incidence, and pelvic tilt) did not significantly change in the 2-years postoperative period. Moreover, age at surgery, the number of resected laminae, preoperative T12–L2 kyphosis, or LL did not affect the postoperative changes in T12–L2 kyphosis or LL, and had no statistically significant correlation among them. The scores of each postoperative JOA domain and the Visual Analogue Scale included in the JOABPEQ were significantly improved. There was no statistical significant group difference in each sagittal profile or clinical outcomes between CM and CE groups postoperatively. Conclusions: Tumor resection using SPSL approach did not affected the various GSSA parameters examined and resulted in satisfactory clinical outcomes, indicating that SPSL approach is a suitable surgical technique for patients with CM or CE tumor.

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Postoperative tongue deviation by hypoglossal nerve palsy and Tapia's syndrome after cervical laminoplasty: report of two cases

Ishihara H., Tsuji O., Okada E., Izawa Y., Kato J., Suzuki S., Takahashi Y., Nori S., Nagoshi N., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 2021

ISSN 09492658

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Myeloperoxidase-antineutrophil cytoplasmic antibody positive hypertrophic spinal pachymeningitis at the cervicothoracic junction: A case report

Ogaki R., Okada E., Suzuki S., Nori S., Tsuji O., Nagoshi N., Yagi M., Watanabe K., Nakamura M., Matsumoto M.

Spine Surgery and Related Research (Spine Surgery and Related Research) 5 ( 3 ) 211 - 213 2021

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The patient demographics, radiographic index and surgical invasiveness for mechanical failure (PRISM) model established for adult spinal deformity surgery

Yagi M., Hosogane N., Fujita N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Nakamura M., Matsumoto M., Watanabe K.

Scientific Reports (Scientific Reports) 10 ( 1 ) 2020.12

Mechanical failure (MF) following adult spinal deformity (ASD) surgery is a severe complication and often requires revision surgery. Predicting a patient’s risk of MF is difficult, despite several potential risk factors that have been reported. The purpose of this study was to establish risk stratification model for predicting the MF based on demographic, and radiographic data. This is a multicenter retrospective review of the risk stratification for MF and included 321 surgically treated ASD patients (55 ± 19 yr, female: 91%). The analyzed variables were recorded for at least 2 yr and included age, gender, BMI, BMD, smoking status, frailty, fusion level, revision surgery, PSO, LIF, previous surgery, spinal alignment, GAP score, Schwab-SRS type, and rod materials. Multivariate logistic regression analyses were performed to identify the independent risk factors for MF. Each risk factor was assigned a value based on its regression coefficient, and the values of all risk factors were summed to obtain the PRISM score (range 0–12). We used an 8:2 ratio to split the data into a training and a testing cohort to establish and validate the model. MF developed in 41% (n = 104) of the training subjects. Multivariate analysis revealed that BMI, BMD, PT, and frailty were independent risk factors for MF (BMI: OR 1.7 [1.0–2.9], BMD: OR 3.8 [1.9–7.7], PT: OR 2.6 [1.8–3.9], frailty: OR 1.9 [1.1–3.2]). The MF rate increased with and correlated well with the risk grade as shown by ROC curve (AUC of 0.81 [95% CI 0.76–0.86]). The discriminative ability of the score in the testing cohort was also good (AUC of 0.86 ([95% CI 0.77–0.95]). We successfully developed an MF-predicting model from individual baseline parameters. This model can predict a patient’s risk of MF and will help surgeons adjust treatment strategies to mitigate the risk of MF.

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Intramedullary endodermal cyst including glial tissues in the spinal cord

Ichihara Y., Nagoshi N., Mikami S., Suzuki S., Tsuji O., Okada E., Yagi M., Watanabe K., Fujita N., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 6 ( 1 ) 2020.12

Introduction: Spinal intramedullary endodermal cyst is a rare spinal cord tumour. In particular, an endodermal cyst that includes glial tissues is extremely rare. Herein, we present the case of an individual with a thoracic spinal cord intramedullary endodermal cyst, which includes glial tissues that achieved gross total resection by surgery. Case presentation: A 59-year-old man presented with a 10-month history of right thigh pain and numbness. Magnetic resonance imaging (MRI) revealed a well-marginated 15-mm cystic lesion at the T7–T8 level. We performed cystectomy and achieved gross total resection. Pathological findings revealed an endodermal cyst, with the presence of glial tissues. No recurrence of cysts was observed upon MRI 2 years after the surgery. Discussion: Endodermal cyst is defined by pathological findings of a cyst lined by columnar epithelium of presumed endodermal derivation. To date, only 104 reported cases of intramedullary endodermal cysts have been reported; our report was the third case that showed the presence of glial cells in the cyst during pathological examination. Intramedullary cysts are generally difficult to completely resect, with many recurrences. Although we achieved gross total resection, careful follow-up is necessary in the future.

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Concurrent dorsal subpial schwannoma and ventral meningioma arising at the same upper cervical level: a case report

Suematsu Y., Tsuji O., Nagoshi N., Nori S., Suzuki S., Okada E., Yagi M., Kameyama K., Fujita N., Watanabe K., Nakamura M., Matsumoto M.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 6 ( 1 ) 2020.12

Introduction: Multiple spinal cord tumors rarely occur without genetic predisposition, and concurrent tumors with discrete pathologies developed at the same spinal level are most rare. Here, we report a case of concurrent dorsal schwannoma and ventral meningioma arising at the same upper cervical level (C1–C2). Case presentation: A 55-year-old woman presented with neck pain and upper and lower extremity numbness for 1 year. Magnetic resonance imaging of the cervical spine showed a partially circumferential C-shaped intradural extramedullary tumor at C1–C2. The preoperative diagnosis based on imaging was intradural extramedullary meningioma with circumferential development. Surgical resection was performed, and dorsal subpial and ventral tumors were detected. Intraoperative pathological diagnosis was schwannoma for the dorsal tumor and meningioma for the ventral tumor. Both tumors were completely resected, followed by circumferential durotomy and duroplasty (Simpson grade 1 resection). Although symptoms related to cerebrospinal fluid hypovolemia occurred immediately after surgery, they disappeared within several days. At 2 years postoperatively, no local recurrence has been identified with mild kyphotic cervical malalignment. Discussions: Only nine cases of concurrent multiple spinal tumors with discrete histopathological types at the same cervical level have been reported to date, however, this is the first case of meningioma combined with subpial schwannoma. Furthermore, although the ventral location of meningioma often compelled inadequate resection leaving behind a dura mater from which meningioma originated, a gross total resection including dura mater was achieved accompanied with circumferential duroplasty. Careful and sequential postoperative follow-up is ongoing for this individual.

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Clinical characteristics in patients with ossification of the posterior longitudinal ligament: A prospective multi-institutional cross-sectional study

Hirai T., Yoshii T., Ushio S., Mori K., Maki S., Katsumi K., Nagoshi N., Takeuchi K., Furuya T., Watanabe K., Nishida N., Watanabe K., Kaito T., Kato S., Nagashima K., Koda M., Ito K., Imagama S., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Watanabe M., Matsumoto M., Nakamura M., Yamazaki M., Okawa A., Kawaguchi Y.

Scientific Reports (Scientific Reports) 10 ( 1 ) 2020.12

Ossification of the posterior longitudinal ligament (OPLL) can occur throughout the entire spine and can sometimes lead to spinal disorder. Although patients with OPLL sometimes develop physical limitations because of pain, the characteristics of pain and effects on activities of daily living (ADL) have not been precisely evaluated in OPLL patients. Therefore, we conducted a multi-center prospective study to assess whether the symptoms of cervical OPLL are different from those of cervical spondylosis (CS). A total of 263 patients with a diagnosis of cervical OPLL and 50 patients with a diagnosis of CS were enrolled and provided self-reported outcomes, including responses to the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), JOA Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS), and SF-36 scores. The severity of myelopathy was significantly correlated with each domain of the JOACMEQ and JOABPEQ. There was a negative correlation between the VAS score for each domain and the JOA score. There were significantly positive correlations between the JOA score and the Mental Health, Bodily Pain, Physical Functioning, Role Emotional, and Role Physical domains of the SF-36. One-to-one matching resulted in 50 pairs of patients with OPLL and CS. Although there was no significant between-group difference in scores in any of the domains of the JOACMEQ or JOABPEQ, the VAS scores for pain or numbness in the buttocks or limbs were significantly higher in the CS group; however, there was no marked difference in low back pain, chest tightness, or numbness below the chest between the two study groups. The scores for the Role Physical and Body Pain domains of the SF-36 were significantly higher in the OPLL group than in the CS group, and the mean scores for the other domains was similar between the two groups. The results of this study revealed that patients with OPLL were likely to have neck and low back pain and restriction in ADL. No specific type of pain was found in patients with OPLL when compared with those who had CS.

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The effect of posterior tethers on the biomechanics of proximal junctional kyphosis: The whole human finite element model analysis

Yagi M., Nakahira Y., Watanabe K., Nakamura M., Matsumoto M., Iwamoto M.

Scientific Reports (Scientific Reports) 10 ( 1 ) 2020.12

Little is known about the effects of posterior tethers on the development of proximal junctional kyphosis (PJK). We evaluated the ability of posterior tethers to the proximal motion segment stiffness in long instrumented spinal instrumentation and fusion using a whole body human FE model. A series of finite element (FE) analysis of long segmental spinal fusion (SF) from the upper thoracic vertebra (T1) or lower thoracic vertebra (T9) to the sacrum with pedicle screws and rods were performed using an entire human body FE model (includes 234,910 elements), and compressive stresses (CS) on the anterior column, and tensile stresses (TS) on the posterior ligamentous complex (PLC) in the upper-instrumented vertebra (UIV) and the vertebra adjacent to the UIV (UIV + 1) were evaluated with posterior tethers or without posterior tethers. The models were tested at three T1 tilts (0, 20, 40 deg.), with 20% muscle contraction. Deformable material models were assigned to all body parts. Muscle-tendon complexes were modeled by truss elements with a Hill-type muscle material model. The CS of anterior column decreased with increasing T1 slope with tethers in both models, while the CS remained relatively large in T9 model compared with T1 model (T1 UIV; 0.96 to 1.56 MPa, T9 UIV; 4.79 to 5.61 MPa). The TS of the supraspinous ligament was markedly reduced in both T1 and T9 models with posterior tethers (11–35%). High vertebral CS on UIV and UIV + 1 were seen in the T9 UIV model, and the TS on the PLC were increased in both UIV models. Posterior tethers may decrease PJK development after SF with a proximal thoracic UIV, while both posterior tethers and vertebral augmentation may be necessary to reduce PJK development with a lower thoracic UIV.

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Associations between clinical symptoms and degree of ossification in patients with cervical ossification of the posterior longitudinal ligament: A prospective multi-institutional cross-sectional study

Hirai T., Yoshii T., Ushio S., Hashimoto J., Mori K., Maki S., Katsumi K., Nagoshi N., Takeuchi K., Furuya T., Watanabe K., Nishida N., Nishimura S., Watanabe K., Kaito T., Kato S., Nagashima K., Koda M., Ito K., Imagama S., Matsuoka Y., Wada K., Kimura A., Ohba T., Katoh H., Watanabe M., Matsuyama Y., Ozawa H., Haro H., Takeshita K., Matsumoto M., Nakamura M., Yamazaki M., Yuasa M., Inose H., Okawa A., Kawaguchi Y.

Journal of Clinical Medicine (Journal of Clinical Medicine) 9 ( 12 ) 1 - 16 2020.12

This study aimed to clarify whether ossification predisposition influences clinical symptoms including pain, restriction of activities of daily living, and quality of life in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Cervical ossification predisposition potentially causes neurologic dysfunction, but the relationship between clinical symptoms and radiologic severity of OPLL has not yet been investigated. Data were prospectively collected from 16 institutions across Japan. We enrolled 239 patients with cervical OPLL. The primary outcomes were patient-reported outcomes, including visual analog scale (VAS) pain scores and other questionnaires. Whole-spine computed tomography images were obtained, and correlations were investigated between clinical symptoms and radiologic findings, including the distribution of OPLL, the sum of the levels where OPLL was present (OP-index), and the canal narrowing ratio (CNR) grade. The cervical OP-index was Grade 1 in 113 patients, Grade 2 in 90, and Grade 3 in 36. No significant correlations were found between radiologic outcomes and VAS pain scores. The cervical OP-index was associated with lower extremity function, social dysfunction, and locomotive function. The CNR grade was not correlated with clinical symptoms, but Grade 4 was associated with lower extremity dysfunction. Thickness and extension of ossified lesions may be associated with lower extremity dysfunction in cervical OPLL.

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Quantitative analysis of intervertebral disc degeneration using Q-space imaging in a rat model

Nakashima D., Fujita N., Hata J., Komaki Y., Suzuki S., Nagura T., Fujiyoshi K., Watanabe K., Tsuji T., Okano H., Jinzaki M., Matsumoto M., Nakamura M.

Journal of Orthopaedic Research (Journal of Orthopaedic Research) 38 ( 10 ) 2220 - 2229 2020.10

ISSN 07360266

The degree of intervertebral disc (IVD) degeneration is qualitatively evaluated on T2-weighted imaging (T2WI). However, it is difficult to assess subtle changes in IVD degeneration using T2WI. Q-space imaging (QSI) is a quantitative diffusion-weighted imaging modality used to detect subtle changes in microenvironments. This study aimed to evaluate whether QSI can detect the inhibitory effects of the antioxidant N-acetylcysteine (NAC) in IVD degeneration. We classified female Wistar rats into control, puncture, and NAC groups (n = 5 per group). In the puncture and NAC groups, IVDs were punctured using a needle. The antioxidant NAC, which suppresses the progression of IVD degeneration, was orally administered in the NAC group 1 week prior to puncture. The progression and inhibitory effect of NAC in IVD degeneration were assessed using magnetic resonance imaging (MRI): IVD height, T2 mapping, apparent diffusion coefficient (ADC), and QSI. MRI was performed using a 7-Tesla system with a conventional probe (20 IVDs in each group). QSI parameters that were assessed included Kurtosis, the probability at zero displacement (ZDP), and full width at half maximum (FWHM). IVD degeneration by puncture was confirmed by histology, IVD height, T2 mapping, ADC, and all QSI parameters (P <.001); however, the inhibitory effect of NAC was confirmed only by QSI parameters (Kurtosis and ZDP: both P <.001; FWHM: P <.01). Kurtosis had the largest effect size (Kurtosis: 1.13, ZDP: 1.06, and FWHM: 1.02) when puncture and NAC groups were compared. QSI has a higher sensitivity than conventional quantitative methods for detecting the progressive change and inhibitory effect of NAC in IVD degeneration.

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Lower Satisfaction After Adult Spinal Deformity Surgery in Japan Than in the United States Despite Similar SRS-22 Pain and Function Scores: A Propensity-Score Matched Analysis

Yagi M., Ames C.P., Hosogane N., Smith J.S., Shaffrey C.I., Schwab F., Lafage V., Bess S., Matsumoto M., Watanabe K.

Spine (Spine) 45 ( 17 ) E1097 - E1104 2020.09

STUDY DESIGN: A multicenter retrospective case series. OBJECTIVE: The purpose of this study was to compare the clinical outcomes of a surgical treatment for adult spinal deformity (ASD) in the United States (US) with those in Japan (JP) in a matched cohort. SUMMARY OF BACKGROUND DATA: Surgical outcomes of thoracic-lumbar-sacral (TLS) spinal fusions in adult spinal deformity ASD patients who live in Asian countries are poorly understood. METHODS: A total of 300 surgically treated ASDs of age more than 50 years with the lowest instrumented vertebra at the pelvis and a minimum follow-up of 2 years (2y) were consecutively included. Patients were propensity-score matched for age, sex, levels fused, and 2y postop sagittal spinal alignment. Demographic, surgical, and radiographic parameters were compared between the US and JP groups. RESULTS: A total of 186 patients were matched by propensity score and were almost identical within these parameters: age (US vs. JP: 66 ± 8 vs. 65 ± 7 yr), sex (females: 90% vs. 89%), levels fused (10 ± 3 vs. 10 ± 2), 2y C7 sagittal vertical axis (C7SVA) (5 ± 5 vs. 5 ± 4 cm), 2y Pelvic incidence minus lumbar lordosis (9 ± 15° vs. 9 ± 15°), and 2y pelvic tilt (PT) (25 ± 10° vs. 24 ± 10°). Oswestry Disability Index (ODI) scores and Scoliosis Research Society patient questionnaire ((SRS-22) function and pain scores were similar at 2y between the US and JP groups (ODI: 27 ± 19% vs. 28 ± 14%, P = 0.72; SRS-22 function: 3.6 ± 0.9 vs. 3.6 ± 0.7, P = 0.54; SRS-22 pain: 3.6 ± 1.0 vs. 3.8 ± 0.8, P = 0.11). However, significantly lower satisfaction was observed in JP than in the US (SRS-22 satisfaction: 4.3 ± 0.9 vs. 4.0 ± 0.8, P < 0.01). CONCLUSION: Surgical treatment for ASD was similarly effective in patients in the US and in JP. However, satisfaction scores were lower in JP compared with the US. Differences in lifestyle and cultural expectations may impact patient satisfaction following ASD surgery.3.

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Chin on chest deformity caused by upper cervical kyphosis associated with ankylosing spondylitis: A case report

Maruiwa R., Watanabe K., Suzuki S., Nori S., Tsuji O., Nagoshi N., Okada E., Yagi M., Fujita N., Nakamura M., Matumoto M.

Neurospine (Neurospine) 17 ( 3 ) 666 - 671 2020.09

ISSN 25866583

Chin on chest deformity caused by upper cervical kyphosis associated with ankylosing spon-dylitis is rare. A 66-year-old woman presented at our institute with chief complaints of diffi-culty in horizontal gaze and opening her mouth. Cervical radiographs showed a C0–2 angle of 1° on flexion and 7° on extension, and her chin-brow vertical angle was 49°. We planned fixation surgery at C0–5 posteriorly to prevent the progression of kyphosis, with slight correction of the kyphosis at C0–2. The correction was performed by pushing down the over lordotically contoured titanium rods connected to an occipital plate onto the C3–5 lateral mass screws, just like cantilever technique. No palpable cracking or loss of resistance was noticed during the correction. However, intraoperative radiographs revealed apparent anterior separation of the vertebral bodies between C3 and C4. Postoperative computed to-mography images at the C3/4 level suggested hemorrhage from the fracture site. Tracheos-tomy was performed because of massive edema around the pharynx. To secure solid bone fusion, staged surgery to extend the fusion to T3 and to graft an additional iliac bone was performed. Fortunately, the C2–7 angle was corrected to 40°, and her chin-brow vertical angle was restored to 17° without any catastrophic complications. Although the patient fi-nally obtained an ideal sagittal alignment, the surgeon should be aware that the technique had a higher perioperative risk for iatrogenic fracture, resulting in neurological and vascu-lar injuries.

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Excessive correction impacts postoperative shoulder imbalance in lenke type 5C adolescent idiopathic scoliosis

Okada E., Suzuki T., Demura S., Saito T., Nohara A., Tsuji T., Uno K., Kawakami N., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 25 ( 5 ) 757 - 762 2020.09

ISSN 09492658

Background: Postoperative shoulder imbalance (PSI) has a negative impact on the surgical outcomes of patients with adolescent idiopathic scoliosis. This study aimed to evaluate the risk factors of PSI in patients with Lenke type 5C curves. Methods: This study included 100 patients who underwent posterior correction surgery using pedicle screw constructs for Lenke type 5C curves. The mean age of the patients at surgery was 15.5 ± 2.3 years, and the mean follow-up period was 36.6 ± 15.0 months. The subjects were classified into the following two groups: PSI and non-PSI. Radiographic parameters, including the preoperative and 2-year postoperative coronal and sagittal profiles, were compared between the two groups. Result: PSI was found in eight patients (8.0%). The preoperative Cobb angles were 47.3° ± 8.7° and 48.0° ± 3.9° in the non-PSI and PSI groups, respectively. The correction rate in the PSI group was significantly higher than that in the non-PSI group (81.0% ± 17.7% vs. 67.7% ± 14.7%; p = 0.018). The preoperative T1 tilt angle in the PSI group was significantly larger than that in the non-PSI group (6.1° ± 3.3° vs. 3.1° ± 2.8°; p = 0.005). Receiver operating characteristic (ROC) analysis showed that the area under the ROC curve was 0.769 (p = 0.012, 95% confidence interval [CI], 0.556–0.982) and 0.763 (p = 0.014, 95% CI, 0.598–0.928) for the correction rate and preoperative T1 tilt, respectively. The cut-off value was 73% and 4° for the correction rate and preoperative T1, respectively. Conclusion: PSI was found in 8.0% of Lenke type 5C curves. Excessive correction of the lumbar curve of >73% and preoperative T1 tilt of >4° can be risk factors for PSI in patients with Lenke type 5C curve.

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Validation study of Rajasekaran's kyphosis classification system: Do we clearly understand single- and two-column deficiencies?

Shetty A.P., Rajavelu R., Viswanathan V.K., Watanabe K., Chhabra H.S., Kanna R.M., Cheung J.P.Y., Hai Y., Kwan M.K., Wong C.C., Liu G., Basu S., Nene A., Naresh-Babu J., Garg B.

Asian Spine Journal (Asian Spine Journal) 14 ( 4 ) 475 - 488 2020.08

ISSN 19761902

Study Design: Multicenter validation study. Purpose: To evaluate the inter-rater reliability of Rajasekaran's kyphosis classification through a multicenter validation study. Overview of Literature: The classification of kyphosis, developed by Rajasekaran, incorporates factors related to curve characteristics, including column deficiency, disc mobility, curve magnitude, and osteotomy requirements. Although the classification offers significant benefits in determining prognosis and management decisions, it has not been subjected to multicenter validation. Methods: A total of 30 sets of images, including plain radiographs, computed tomography scans, and magnetic resonance imaging scans, were randomly selected from our hospital patient database. All patients had undergone deformity correction surgery for kyphosis. Twelve spine surgeons from the Asia-Pacific region (six different countries) independently evaluated and classified the deformity types and proposed their surgical recommendations. This information was then compared with standard deformity classification and surgical recommendations. Results: The kappa coefficients for the classification were as follows: 0.88 for type 1A, 0.78 for type 1B, 0.50 for type 2B, 0.40 for type 3A, 0.63 for type 3B, and 0.86 for type 3C deformities. The overall kappa coefficient for the classification was 0.68. Regarding the repeatability of osteotomy recommendations, kappa values were the highest for Ponte's (Schwab type 2) osteotomy (kappa 0.8). Kappa values for other osteotomy recommendations were 0.52 for pedicle subtraction/disc-bone osteotomy (Schwab type 3/4), 0.42 for vertebral column resection (VCR, type 5), and 0.30 for multilevel VCRs (type 6). Conclusions: Excellent accuracy was found for types 1A, 1B, and 3C deformities (ends of spectrum). There was more variation among surgeons in differentiating between one-column (types 2A and 2B) and two-column (types 3A and 3B) deficiencies, as surgeons often failed to recognize the radiological signs of posterior column failure. This failure to identify column deficiencies can potentially alter kyphosis management. There was excellent consensus among surgeons in the recommendation of type 2 osteotomy; however, some variation was observed in their choice for other osteotomies.

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Short fusion with vertebrectomy during growth in congenital spinal deformity: is early surgical intervention recommended?

Matsumoto H., Kawakami N., Saito T., Uno K., Suzuki T., Watanabe K., Matsumoto M., Yamaguchi T., Yanagida H., Kotani T., Demura S., Takeshita K., Taniguchi Y.

Spine Deformity (Spine Deformity) 8 ( 4 ) 733 - 742 2020.08

ISSN 2212134X

Study design: This was a multi-center retrospective cohort study included consecutive pediatric patients who were admitted to 8 institutions for the treatment of congenital spinal deformity from 1991 to 2012. Objective: The purpose of this study was to compare curve corrections and balances, reoperations, and complications at 2-year follow-up between those treated early vs. late. Summary of background data: Although early intervention has been recommended, no empirical study has examined the optimal timing of short fusion among patients with congenital spinal deformity. Methods: Patients with congenital spinal deformity with formation failure undergoing vertebrectomy with short fusion (≤ 6 fusion segments) were categorized as early (surgery at ≤ 6 years) and late (7–18 years) fusion. Outcomes included coronal and sagittal curve corrections at immediate and 2-year evaluations; loss of curve correction from immediate to 2-year follow-up; coronal and sagittal balance at 2 years; and inter-operative, major and minor short-term postoperative, and long-term postoperative complications and reoperations. Results: Early fusion (N = 79) compared to late fusion (N = 96) was associated with greater percent curve correction at immediate (71% vs. 60%, p = 0.0046) and 2-year (63% vs. 52%, p = 0.0153) evaluations adjusting for surgeon experience and preoperative coronal balance. These associations were significant for males and those with 3-level fusions but not 4 to 6-level fusions. Early fusion compared with late fusion had more intraoperative (6% vs. 1%) and postoperative long-term complications (27% vs. 18%), as well as unplanned reoperations (13% vs. 9%). Early vs. late fusion had fewer short-term complications, both major (6% vs. 15%) and minor (6% vs. 15%). Conclusions: Patients who underwent early treatment achieved larger major curve correction by 10% compared to patients with late treatment when assessed at 2-year postoperative evaluation. However, early fusion should be considered with careful attention to possible increased risk of reoperations. Level of evidence: Level III.

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Short- versus long-segment posterior spinal fusion with vertebroplasty for osteoporotic vertebral collapse with neurological impairment in thoracolumbar spine: A multicenter study

Ishikawa Y., Watanabe K., Katsumi K., Ohashi M., Shibuya Y., Izumi T., Hirano T., Endo N., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Matsuoka Y., Suzuki H., Nishimura H., Terai H., Tamai K., Tagami A., Yamada S., Adachi S., Yoshii T., Ushio S., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Kimura A., Inoue H., Inoue G., Miyagi M., Saito W., Nakano A., Sakai D., Nukaga T., Ikegami S., Shimizu M., Futatsugi T., Ohtori S., Furuya T., Orita S., Imagama S., Ando K., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Oshima M., Takahata M., Iwata A., Endo H., Abe T., Tsukanishi T., Nakanishi K., Watanabe K., Hikata T., Suzuki S., Isogai N., Okada E., Funao H., Ueda S., Shiono Y., Nojiri K., Hosogane N., Ishii K.

BMC Musculoskeletal Disorders (BMC Musculoskeletal Disorders) 21 ( 1 ) 2020.08

Background: Vertebroplasty with posterior spinal fusion (VP + PSF) is one of the most widely accepted surgical techniques for treating osteoporotic vertebral collapse (OVC). Nevertheless, the effect of the extent of fusion on surgical outcomes remains to be established. This study aimed to evaluate the surgical outcomes of short- versus long-segment VP + PSF for OVC with neurological impairment in thoracolumbar spine. Methods: We retrospectively collected data from 133 patients (median age, 77 years; 42 men and 91 women) from 27 university hospitals and their affiliated hospitals. We divided patients into two groups: a short-segment fusion group (S group) with 2- or 3-segment fusion (87 patients) and a long-segment fusion group (L group) with 4- through 6-segment fusion (46 patients). Surgical invasion, clinical outcomes, local kyphosis angle (LKA), and complications were evaluated. Results: No significant differences between the two groups were observed in terms of neurological recovery, pain scale scores, and complications. Surgical time was shorter and blood loss was less in the S group, whereas LKA at the final follow-up and correction loss were superior in the L group. Conclusion: Although less invasiveness and validity of pain and neurological relief are secured by short-segment VP + PSF, surgeons should be cautious regarding correction loss.

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Murata K., Matsuoka Y., Nishimura H., Endo K., Suzuki H., Takamatsu T., Sawaji Y., Aihara T., Kusakabe T., Maekawa A., Yamamoto K., Watanabe K., Kaito T., Terai H., Tamai K., Tagami A., Yoshii T., Harimaya K., Kawaguchi K., Kimura A., Inoue G., Nakano A., Sakai D., Hiyama A., Ikegami S., Ohtori S., Furuya T., Orita S., Imagama S., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Uei H., Ajiro Y., Takahata M., Endo H., Abe T., Nakanishi K., Watanabe K., Okada E., Hosogane N., Funao H., Isogai N., Ishii K.

European Spine Journal (European Spine Journal) 29 ( 7 ) 1597 - 1605 2020.07

ISSN 09406719

Purpose: Osteoporotic vertebral fracture (OVF) with nonunion or neurological deficit may be a candidate for surgical treatment. However, some patients do not show improvement as expected. Therefore, we conducted a nationwide multicenter study to determine the predictors for postoperative poor activity of daily living (ADL) in patients with OVF. Methods: We retrospectively reviewed the case histories of 309 patients with OVF who underwent surgery. To determine the factors predicting postoperative poor ADL, uni- and multivariate statistical analyses were performed. Results: The frequency of poor ADL at final follow-up period was 9.1%. In univariate analysis, preoperative neurological deficit (OR, 4.1; 95% CI, 1.8–10.3; P < 0.001), perioperative complication (OR, 3.4; P = 0.006), absence of preoperative bone-modifying agent (BMA) administration (OR, 2.7; P = 0.03), and absence of postoperative recombinant human parathyroid hormone (rPTH) administration (OR, 3.9; P = 0.006) were significantly associated. In multivariate analysis, preoperative neurological deficit (OR, 4.6; P < 0.001), perioperative complication (OR, 3.4; P = 0.01), and absence of postoperative rPTH administration (OR, 3.9; P = 0.02) showed statistical significance. Conclusions: Preoperative neurological deficit, perioperative complication, and absence of postoperative rPTH administration were considered as predictors for postoperative poor ADL in patients with OVF. Neurological deficits and complications are often inevitable factors; therefore, rPTH is an important option for postoperative treatment for OVF. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.]

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Effect of bisphosphonates or teriparatide on mechanical complications after posterior instrumented fusion for osteoporotic vertebral fracture: A multi-center retrospective study

Kawabata A., Yoshii T., Yoshii T., Hirai T., Ushio S., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Matsuoka Y., Suzuki H., Nishimura H., Terai H., Tamai K., Tagami A., Yamada S., Adachi S., Watanabe K., Katsumi K., Ohashi M., Shibuya Y., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Kimura A., Inoue H., Inoue G., Miyagi M., Saito W., Nakano A., Sakai D., Nukaga T., Ikegami S., Shimizu M., Futatsugi T., Ohtori S., Furuya T., Orita S., Imagama S., Ando K., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Oshima M., Takahata M., Iwata A., Endo H., Abe T., Tsukanishi T., Nakanishi K., Watanabe K., Hikata T., Suzuki S., Isogai N., Isogai N., Okada E., Funao H., Ueda S., Shiono Y., Nojiri K., Hosogane N., Ishii K., Ishii K.

BMC Musculoskeletal Disorders (BMC Musculoskeletal Disorders) 21 ( 1 ) 2020.07

Background: The optimal treatment of osteoporosis after reconstruction surgery for osteoporotic vertebral fractures (OVF) remains unclear. In this multicentre retrospective study, we investigated the effects of typically used agents for osteoporosis, namely, bisphosphonates (BP) and teriparatide (TP), on surgical results in patients with osteoporotic vertebral fractures. Methods: Retrospectively registered data were collected from 27 universities and affiliated hospitals in Japan. We compared the effects of BP vs TP on postoperative mechanical complication rates, implant-related reoperation rates, and clinical outcomes in patients who underwent posterior instrumented fusion for OVF. Data were analysed according to whether the osteoporosis was primary or glucocorticoid-induced. Results: A total of 159 patients who underwent posterior instrumented fusion for OVF were included. The overall mechanical complication rate was significantly lower in the TP group than in the BP group (BP vs TP: 73.1% vs 58.2%, p = 0.045). The screw backout rate was significantly lower and the rates of new vertebral fractures and pseudoarthrosis tended to be lower in the TP group than in the BP group. However, there were no significant differences in lumbar functional scores and visual analogue scale pain scores or in implant-related reoperation rates between the two groups. The incidence of pseudoarthrosis was significantly higher in patients with glucocorticoid-induced osteoporosis (GIOP) than in those with primary osteoporosis; however, the pseudoarthrosis rate was reduced by using TP. The use of TP also tended to reduce the overall mechanical complication rate in both primary osteoporosis and GIOP. Conclusions: The overall mechanical complication rate was lower in patients who received TP than in those who received a BP postoperatively, regardless of type of osteoporosis. The incidence of pseudoarthrosis was significantly higher in patients with GIOP, but the use of TP reduced the rate of pseudoarthrosis in GIOP patients. The use of TP was effective to reduce postoperative complications for OVF patients treated with posterior fusion.

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Changes in cervical spinal alignment after thoracolumbar corrective surgery in adult patients with adolescent idiopathic scoliosis

Nagoshi N., Yagi M., Daimon K., Suzuki S., Tsuji O., Okada E., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 45 ( 13 ) 877 - 883 2020.07

ISSN 03622436

Study Design.Case-control study.Objective.To examine factors influencing cervical alignment after corrective surgery for adult patients with adolescent idiopathic scoliosis (AdIS)Summary of Background Data.Corrective surgery for spinal deformity influences postoperative cervical spinal alignment, but changes in the cervical alignment in adults with AdIS are scarcely reported.Methods.We retrospectively examined 85 patients with AdIS who underwent posterior corrective surgery for thoracic or lumbar major curve and were followed up for 2 years. Clinical characteristics, radiographic parameters, and health-related quality of life (HRQOL) were evaluated. Cervical deformity (CD) was defined as one of the following cases: (1) T1 tilt minus C2-C7 angle more than 20°, (2) C2-C7 SVA more than 40mm, (3) and C2-C7 angle less than-10°. Patients were divided into those with and without CD based on the defined criteria; statistically relevant factors were analyzed.Results.There were 19 patients in the postoperative CD group. The average age at the time of surgery was lower in the CD group (26.5 vs. 31.4). In the CD group, the average preoperative T1 tilt was smaller (1.1° vs. 12.5°), and the C2-C7 angle was kyphotic (-16.1° vs. 3.0°). The average kyphotic angle at thoracic spine (T5-T12) was lower in the CD group preoperatively (12.5° vs. 19.5°) and postoperatively (15.2° vs. 20.8°). HRQOL outcomes were comparable between the groups. Of the patients with preoperative CD, 51.5% (n=17) maintained their deformity at the final follow-up, and baseline C2-C7 angle was lower than those who converted to non-CD following surgery (n=16) (-17.0° vs.-10.3°).Conclusion.More than half of the patients with baseline CD maintained their cervical malalignment postoperatively. Patients with postoperative CD presented cervical kyphotic and thoracic hypokyphotic alignments before surgery. Because CD has the potential to lead to cervical degeneration, careful follow-up observation is necessary for these young patients.Level of Evidence: 3.

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Comparison of Pulmonary Function After Selective Anterior Versus Posterior Fusion for the Correction of Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis

Demura S., Watanabe K., Suzuki T., Saito T., Yamamoto T., Kotani T., Nohara A., Tsuji T., Ogura Y., Tsuchiya H., Uno K., Matsumoto M., Kawakami N.

Global Spine Journal (Global Spine Journal) 10 ( 4 ) 433 - 437 2020.06

ISSN 21925682

Study Design: Retrospective multicenter study. Objectives: To compare the selective anterior spinal fusion (ASF) versus posterior spinal fusion (PSF) on postoperative pulmonary function testing (PFT) whether thoracotomy with separation of the diaphragm by anterior approach influences the PFT in thoracolumbar and lumbar adolescent idiopathic scoliosis (AIS). Methods: A multicenter series of AIS patients who underwent selective spinal fusion were retrospectively reviewed. Seventy-nine female patients were included (mean 15.8 years). There were 35 patients in the ASF group and 44 patients in the PSF group. Patient demographics, radiographic measurements, and PFT data from preoperative to 2-year follow-up were analyzed. Results: Preoperatively, there were no significant differences in PFTs between the groups. The ASF group patients were more likely to undergo shorter fusions (4.5 instrumented vertebral levels) than those in the PSF group (5.2 levels). At 2-year follow-up, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) in ASF group were statistically lower than those in PSF group. When comparing preoperative and 2-year changes on each procedure, only %FVC showed significant difference in ASF while FVC, FEV1, and %FEV1 did not. Meanwhile, the ASF group showed a significant decrease in FVC at 6 and 12 months compared to preoperative values. In PSF group, there was a decrease at 6 months, returned to preoperative value at 1-year follow-up. Conclusions: Pulmonary function after ASF and PSF was similar at 2 years; however, anterior group did not return to the baseline at 6 months and 1 year suggesting anterior approach may affect early postoperative pulmonary function.

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Reaching minimal clinically important difference in adult spinal deformity surgery: A comparison of patients from North America and Japan

Arima H., Glassman S.D., Bridwell K., Yamato Y., Yagi M., Watanabe K., Matsumoto M., Inami S., Taneichi H., Matsuyama Y., Carreon L.Y.

Journal of Neurosurgery: Spine (Journal of Neurosurgery: Spine) 32 ( 6 ) 859 - 864 2020.06

ISSN 15475654

OBJECTIVE The Scoliosis Research Society-22r questionnaire (SRS-22r) has been shown to be reliable, valid, and responsive to change in patients with adult spinal deformity (ASD) undergoing surgery. The minimal clinically important difference (MCID) is the smallest difference in a health-related quality of life score that is considered to be worthwhile or clinically important to the individual. The authors hypothesized that the proportion of patients with ASD achieving an MCID in the SRS-22r score would be different between two culturally different cohorts. The purpose of this study was to compare the proportion of patients with ASD achieving MCID for the SRS-22r domains in North American (NA) and Japanese cohorts. METHODS A total of 137 patients from North America (123 women, mean age 60.0 years) and 60 patients from Japan (56 women, mean age 65.5 years) with at least 2 years of follow-up after corrective spine surgery for ASD were included. Except for self-image, published Japanese MCID values of SRS-22r for ASD were higher (function = 0.90, pain = 0.85, self-image = 1.05, subtotal = 1.05) than the published NA MCID values (function = 0.60, pain = 0.40, self-image = 1.23, subtotal = 0.43). RESULTS There was a statistically significant improvement in all SRS-22r domain scores at 2 years compared to baseline in both cohorts. Except for mental health (NA = 0.32, Japanese = 0.72, p = 0.005), the mean improvement from baseline to 2 years was similar between the NA and Japanese cohorts. The proportion of patients achieving MCID was higher in North America for function (NA = 51%, Japanese = 30%, p = 0.006), pain (NA = 80%, Japanese = 47%, p < 0.001), and subtotal (NA = 72%, Japanese = 35%, p < 0.001), while there was no significant difference for self-image (NA = 53%, Japanese = 58%, p = 0.454). CONCLUSIONS Despite similar improvements in SRS-22r domain scores from baseline to 2 years postoperatively, the proportion of patients reaching SRS-22r MCID for function, pain, and subtotal after ASD surgery was higher in the NA cohort than in the Japanese cohort. This may imply that patients in North America and Japan may value observed changes in clinical status differently.

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Impact of knee osteoarthritis on surgical outcomes of lumbar spinal canal stenosis

Ozaki M., Fujita N., Miyamoto A., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Tsuji T., Nakamura M., Matsumoto M., Kono H., Watanabe K.

Journal of Neurosurgery: Spine (Journal of Neurosurgery: Spine) 32 ( 5 ) 710 - 715 2020.05

ISSN 15475654

OBJECTIVE Lumbar spinal canal stenosis (LSS) and knee osteoarthritis (KOA), both of which are age-related degenerative diseases, are independently correlated with increased pain and dysfunction of the lower extremities. However, there have been few studies that investigated whether LSS patients with KOA exhibit poor clinical recovery following lumbar spinal surgery. The aim of this study was to elucidate the surgical outcomes of lumbar spinal surgery for LSS patients with KOA using multiple health-related quality of life (HRQOL) parameters. METHODS A total of 865 consecutive patients who underwent posterior lumbar spinal surgery for LSS were retrospectively reviewed. Baseline characteristics, radiographic parameters, perioperative factors, and multiple HRQOL parameters were analyzed preoperatively and at 1-year follow-up. HRQOL items included the Zurich Claudication Questionnaire, Oswestry Disability Index, Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The effectiveness of surgical treatment was assessed using the JOABPEQ. The treatment was regarded as effective when it resulted in an increase in postoperative JOABPEQ score by ≥ 20 points compared with preoperative score or achievement of a postoperative score of ≥ 90 points in those with a preoperative score of < 90 points. RESULTS A total of 32 LSS patients with KOA were identified, and 128 age- and sex-matched LSS patients without KOA were selected as controls. In both groups, all HRQOL parameters markedly improved at the 1-year follow-up. On the SF-36, the postoperative mean score for the role physical domain was significantly lower in the KOA group than in the control group (p = 0.034). The treatment was significantly less “effective” in the social life domain of JOABPEQ in the KOA group than in the control group (p < 0.001). CONCLUSIONS The surgical outcomes of LSS patients with KOA are favorable, although poorer than those of LSS patients without KOA, particularly in terms of social life and activities. These results indicate that LSS patients with KOA experience difficulty in routine work or ordinary activities due to knee pain or restricted knee ROM even after lumbar spinal surgery. Hence, preoperative KOA status warrants consideration when planning lumbar spinal surgery and estimating surgical outcomes of LSS.

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Patients majoring in a healthcare field after scoliosis surgery: Comparison with the national census in Japan

Kotani T., Sakuma T., Nakayama K., Iijima Y., Watanabe K., Isogai N., Akazawa T., Sato K., Asada T., Kishida S., Muramatsu Y., Sasaki Y., Ueno K., Katogi T., Minami S., Inage K., Shiga Y., Ohtori S.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 25 ( 3 ) 394 - 399 2020.05

ISSN 09492658

Background: Although scoliosis surgery early in life may affect the career choice of the patient in favor of a healthcare field, no study has analyzed this relationship. We investigated the career paths of patients after scoliosis surgery. Methods: A total of 212 patients with scoliosis who underwent corrective surgery at 12–17 years of age were mailed a questionnaire, of whom 98 (mean age at survey: 21.0 ± 1.7, years) responded. Choice of study major was determined by the same questions used in the Japanese national census. Results: Of the 98 patients, 35% chose a career in healthcare compared with 11% of the general population of the same age, based on the national census. Healthcare was the most popular career choice of patients, whereas it ranked fourth according to the national census. Furthermore, 87% of patients reported that their decision to pursue a healthcare-related career was affected by their own medical experiences. Among the healthcare-related occupations, nursing ranked first, accounting for 35% of all healthcare professions chosen by the patients. Compared with patients who chose a non-healthcare career, those choosing a healthcare career decided on their study major at a significantly lower age. Conclusions: One-third of patients with scoliosis who underwent spine surgery chose a career in a healthcare field. Furthermore, an earlier age at the time of making a career decision was a significant factor associated with choosing a healthcare career. These findings suggest that the patients' experiences in the hospital positively affected their future career paths.

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Potential association of metabolic and musculoskeletal disorders with lumbar intervertebral disc degeneration: Cross-sectional study using medical checkup data

Fujita N., Ishihara S., Michikawa T., Azuma K., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Tsuji T., Takayama M., Matsumoto H., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 25 ( 3 ) 384 - 388 2020.05

ISSN 09492658

Background: The pathogenesis of intervertebral disc (IVD) degeneration is complex and involves the interaction of multiple factors. However, few systemic studies have explored the associations of metabolic disorders and age-related musculoskeletal disorders with the development of IVD degeneration. Methods: We analyzed clinical data obtained from healthy individuals who had undergone a musculoskeletal checkup. In total, 276 subjects comprising 142 males and 134 females were enrolled. The subjects were divided into two groups based on the degree of IVD degeneration according to Pfirrmann grading: those with grades 1–3, the group with non-degenerative discs; and grades 4 and 5, the group with degenerative discs. The subjects underwent examinations including abdominal circumference, blood pressure, bilateral hand grip strength, abdominal computed tomography, magnetic resonance imaging of the lumbar spine, and dual X-ray absorptiometry. To examine the independent association with IVD degeneration at L3/4, L4/5, and L5/S levels, we constructed a Poisson regression model and estimated relative risks (RRs) and 95% confidence intervals (CIs) of IVD degeneration. Results: Multivariable analysis showed that advanced age was markedly associated with IVD degeneration at all levels and that men had an inverse association with the IVD degeneration, particularly at the L4/5 level (RR = 0.7, 95% CI = 0.6–0.9). In addition, metabolic syndrome was significantly associated with IVD degeneration at the L5/S level (RR = 1.4, 95% CI = 1.1–1.8). Meanwhile, sarcopenia showed no significant association with IVD degeneration at any level. Osteoporosis was inversely associated with IVD degeneration, particularly at the L4/5 level (RR = 0.7, 95% CI = 0.6–0.9). Conclusions: Our data suggest that advanced age, female sex, and metabolic syndrome are associated with IVD degeneration. In addition, osteoporosis showed an inverse association with IVD degeneration. Our data should promote understanding of the etiology of lumbar IVD degeneration.

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Characteristic cerebral structural changes identified using voxel-based morphometry in patients with post-surgical chronic myelopathic pain

Horiuchi Y., Tsuji O., Komaki Y., Fujiyoshi K., Hikishima K., Konomi T., Nagoshi N., Watanabe K., Matsumoto M., Horiuchi K., Nakamura M.

Spinal Cord (Spinal Cord) 58 ( 4 ) 467 - 475 2020.04

ISSN 13624393

Study Design: Cross-sectional study. Objective: Patients who undergo intramedullary spinal surgery occasionally experience post-surgical chronic pain; however, the underlying mechanisms are not yet completely understood. Therefore, this study aimed to identify the cerebral structural changes in patients with post-surgical chronic myelopathic pain using voxel-based morphometry. Setting: Single university hospital in Tokyo, Japan. Methods: Forty-nine patients who had undergone intramedullary spinal surgery between January 2002 and April 2014 participated in this study. Participants were classified into two groups based on their post-surgical chronic pain intensity: control (numeric rating scale score of <3) and pain (numeric rating scale score of ≥3) groups. We compared pain questionnaire and brain MRI between two groups. Brain MRI data of each participants was analyzed using voxel-based morphometry. Results: Voxel-based morphometry revealed that the gray matter volume in the left supplementary motor area, left primary motor area, and left posterior cingulate cortex was higher in the pain group than that in the control group. In addition, the numeric rating scale score was significantly correlated with increased gray matter volume in the left primary motor area, left posterior cingulate cortex, and right superior parietal lobule. Conclusion: Present study elucidates the characteristic cerebral structural changes after an intramedullary spinal surgery using voxel-based morphometry and indicates that the structural changes in specific cerebral areas are associated with post-surgical chronic myelopathic pain.

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Midterm surgical outcomes of a short fusion strategy for adolescent idiopathic scoliosis with Lenke 5C curve

Ogura Y., Okada E., Fujii T., Yagi M., Fujita N., Suzuki S., Hosogane N., Kitagawa T., Tsuji O., Nagoshi N., Nakamura M., Matsumoto M., Watanabe K.

Spine Journal (Spine Journal) 20 ( 3 ) 361 - 368 2020.03

ISSN 15299430

BACKGROUND CONTEXT: A previous study examined the short-term (2 years) outcomes of a short fusion strategy for Lenke type 5C curves. This strategy had a little less correction rate with no difference in coronal and sagittal balance and SRS-22 scores to those of a conventional strategy and was superior in operative time and intraoperative bleeding. However, its effectiveness in longer follow-up periods was unknown. PURPOSE: To assess midterm surgical outcomes of a short fusion strategy for adolescent idiopathic scoliosis (AIS) with Lenke type 5C curve, involving posterior correction and fusion surgery (PSF) using pedicle-screw constructs. STUDY DESIGN: Retrospective case series. PATIENT SAMPLE: Twenty-nine patients who underwent PSF for AIS with Lenke type 5C curve with a minimum 5-year follow-up. OUTCOME MEASURES: Radiographic parameters and SRS-22. METHODS: We compared radiographic parameters and clinical outcomes between patients with an upper instrumented vertebra (UIV) at the end vertebra (EV) (n=12) and those treated by short fusion (S), with a UIV one level caudal to the EV (n=17). RESULTS: A preoperative mean Cobb angle of 51.9±13.8° was corrected to 11.7±7.7° in the EV group, and an angle of 46.0±6.6° was corrected to 9.3±5.2° in the S group. The correction was maintained in both groups at the final follow-up, and the mean correction loss was 2.8±6.8° in the EV and 6.5±6.5° in the S group (p=.143). The mean correction rate at the final follow-up was not significantly different between the EV (71.4±11.8%) and S (64.9±13.7%) groups (p=.199). A Cobb angle of a thoracic curve was significantly improved immediately after surgery and maintained during the follow-up period in the both groups. Coronal and sagittal balance, thoracic kyphosis, lumbar lordosis, L4 tilt, UIV/LIV tilt, shoulder balance, and SRS-22 had no difference between the two groups. CONCLUSIONS: There was no difference in radiographic parameters and SRS-22 between patients treated with a UIV at the UEV and patients treated using a short fusion strategy, in which the UIV was one level caudal to the UEV. The short fusion strategy can be one of the alternatives in PSF for Lenke type 5C curves, at least in 5-year time frame.

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Clinical Outcomes, Complications, and Cost-effectiveness in Surgically Treated Adult Spinal Deformity over 70 Years: A Propensity score-Matched Analysis

Yagi M., Fujita N., Okada E., Tsuji O., Nagoshi N., Asazuma T., Nakamura M., Matsumoto M., Watanabe K.

Clinical Spine Surgery (Clinical Spine Surgery) 33 ( 1 ) E14 - E20 2020.02

ISSN 23800186

Study Design:This is a multicentered retrospective study.Summary of Background Data:Surgical correction for the adult spinal deformity (ASD) is effective but carries substantial risks for complications. The diverse pathologies of ASD make it difficult to determine the effect of advanced age on outcomes.Objective:The objective of this study was to assess how advanced age affects outcomes and cost-effectiveness for corrective surgery for ASD.Materials and Methods:We used data from a multicenter database to conduct propensity score-matched comparisons of 50 patients who were surgically treated for ASD when at least 50 years old and were followed for at least 2 years, to clarify whether advanced age is a risk factor for inferior health-related quality of life and cost-effectiveness. Patients were grouped by age, 50-65 years (M group: 59±4 y) or >70 years (O group: 74±3 y), and were propensity score-matched for sex, body mass index, upper and lower instrumented vertebrae, the use of pedicle-subtraction osteotomy, and sagittal alignment. Cost-effectiveness was determined by cost/quality-adjusted life years.Results:Oswestry Disability Index and Scoliosis Research Society-22 (SRS-22) pain and self-image at the 2-year follow-up were significantly inferior in the O group (Oswestry Disability Index: 32±9% vs. 25±13%, P=0.01; SRS-22 pain: 3.5±0.7 vs. 3.9±0.6, P=0.05; SRS-22 self-image: 3.5±0.6 vs. 3.8±0.9, P=0.03). The O group had more complications than the M group (55% vs. 29%). The odds ratios in the O group were 4.0 for postoperative complications (95% confidence interval: 1.1-12.3) and 4.9 for implant-related complications (95% confidence interval: 1.2-21.1). Cost-utility analysis at 2 years after surgery indicated that the surgery was less cost-effective in the O group (cost/quality-adjusted life year: O group: $211,636 vs. M group: 125,887, P=0.01).Conclusions:Outcomes for corrective surgery for ASD were inferior in geriatric patients compared with middle-aged patients, in whom the extent of spinal deformity and the operation type were adjusted similarly. Special attention is needed when considering surgical treatment for geriatric ASD patients.

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Outcomes of Surgery for Thoracic Myelopathy Owing to Thoracic Ossification of the Ligamentum Flavum in a Nationwide Multicenter Prospectively Collected Study in 223 Patients: Is Instrumented Fusion Necessary?

Ando K., Imagama S., Kaito T., Takenaka S., Sakai K., Egawa S., Shindo S., Watanabe K., Fujita N., Matsumoto M., Nakashima H., Wada K., Kimura A., Takeshita K., Kato S., Murakami H., Takeuchi K., Takahata M., Koda M., Yamazaki M., Watanabe M., Fujibayashi S., Furuya T., Kawaguchi Y., Matsuyama Y., Yoshii T., Okawa A.

Spine (Spine) 45 ( 3 ) E170 - E178 2020.02

ISSN 03622436

Study Design.Prospectively collected, multicenter, nationwide study.Objective.The aim of this study was to investigate recent surgical methods and trends, outcomes, and perioperative complications in surgery for thoracic ossification of the ligamentum flavum (T-OLF).Summary of Background Data.A prospective multicenter study of surgical complications and risk factors for T-OLF has not been performed, and previous multicenter retrospective studies have lacked details for these items.Methods.Surgical methods, pre- A nd postoperative thoracic myelopathy (Japanese Orthopedic Association [JOA] score), symptoms, and intraoperative neurophysiological monitoring were investigated prospectively in 223 cases. Differences in these factors between fusion and nonfusion procedures for T-OLF were examined. The minimum follow-up period was 2 years after surgeryResults.The mean JOA score was 6.2 points preoperatively, and 7.9, 8.2, and 8.2 points at 6 months, 1, and 2 year postoperatively, giving mean recovery rates of 35.0%, 40.9%, and 41.4% respectively. Posterior decompression and fusion with instrumentation was performed in 109 cases (48.9%). There were 45 perioperative complications in 30 cases (13.5%), with aggravation of motor disturbance in the lower extremities being most common (4.0%, n=9). Patients treated with fusion had a significantly higher BMI, rate of gait disturbance, ossification occupation rate of OLF at computed tomography, and intramedullary high intensity area at magnetic resonance imaging (P<0.01). The preoperative JOA score was lower (P<0.05) and the JOA recovery rate at 1 year after surgery was significantly higher in cases treated without fusion (44.9% vs. 37.1%, P<0.05).Conclusion.The high rate of surgery with instrumentation of 48.9% reflects the current major trend toward posterior instrumented fusion surgery for T-OLF. Fusion surgery with instrumentation may be appropriate for patients with severe OLF and preoperative myelopathy. A further prospective study of long-term outcomes is required with a focus on optimal surgical timing and the surgical procedure for T-OPLL.Level of Evidence: 3.

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Risk Factors for Postoperative Distal Adding-on in Lenke Type 1B and 1C and its Influence on Residual Lumbar Curve

Fujii T., Daimon K., Fujita N., Yagi M., Michikawa T., Hosogane N., Nagoshi N., Tsuji O., Kaneko S., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Journal of Pediatric Orthopaedics (Journal of Pediatric Orthopaedics) 40 ( 2 ) e77 - e83 2020.02

ISSN 02716798

Background:Distal adding-on (DA) in adolescent idiopathic scoliosis is a radiographic complication that can negatively affect clinical results. However, the risk factors for DA and the influences of DA on the residual lumbar curves have not been fully elucidated in Lenke type 1B and 1C curves. The objective of this study was to investigate risk factors for postoperative DA in Lenke type 1B and 1C curves, and the influence of DA on residual lumbar curves.Methods:We retrospectively evaluated 46 adolescent idiopathic scoliosis patients with Lenke type 1B or 1C curves who underwent posterior correction and fusion surgery with selective thoracic fusion. Patients were grouped according to the presence or absence of DA on radiographs at the 2-year follow-up. We compared coronal radiographic parameters between the 2 groups, including the Cobb angle, L4 tilt angle, apical translation, and relative positions of the end vertebra (EV), stable vertebra (SV), neutral vertebra (NV), and last touching vertebra (LTV) to the lower instrumented vertebra (LIV).Results:DA was present in 11 patients (24%) at the 2-year follow-up, and the mean LIV-EV, LIV-NV, LIV-SV, and LIV-LTV relative positions were significantly smaller in the DA than in the non-DA group. Preoperative radiographic parameters were similar between the 2 groups, including the mean L4 tilt angle (non-DA,-8±4 degrees; DA,-7±4 degrees). At the 2-year follow-up, the mean apical translation of the lumbar curve was smaller in the DA group (non-DA,-16±8 mm; DA,-7±11 mm) and the mean L4 tilt angle was significantly more horizontalized (non-DA,-8±4 degrees; DA,-1±5 degrees). Multivariate analysis showed that the number of levels between the LIV and LTV (LIV-LTV) was significantly associated with DA.Conclusions:A LIV at or cranial to the LTV was a significant risk factor for postoperative DA in Lenke type 1B and 1C curves. Spontaneous correction of the residual lumbar curve was superior in patients with DA.

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The surgical outcomes of spinal fusion for osteoporotic vertebral fractures in the lower lumbar spine with a neurological deficit

Isogai N., Hosogane N., Funao H., Nojiri K., Suzuki S., Okada E., Ueda S., Hikata T., Shiono Y., Watanabe K., Watanabe K., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Terai H., Tamai K., Matsuoka Y., Suzuki H., Nishimura H., Tagami A., Yamada S., Adachi S., Ohtori S., Orita S., Furuya T., Yoshii T., Ushio S., Inoue G., Miyagi M., Saito W., Imagama S., Ando K., Sakai D., Nukaga T., Kiyasu K., Kimura A., Inoue H., Nakano A., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Ikegami S., Shimizu M., Futatsugi T., Kakutani K., Yurube T., Oshima M., Uei H., Aoki Y., Takahata M., Iwata A., Seki S., Murakami H., Yoshioka K., Endo H., Hongo M., Nakanishi K., Abe T., Tsukanishi T., Ishii K.

Spine Surgery and Related Research (Spine Surgery and Related Research) 4 ( 3 ) 199 - 207 2020.01

Introduction: Osteoporotic vertebral fracture (OVF) is the most common osteoporotic fracture, and some patients require surgical intervention to improve their impaired activities of daily living with neurological deficits. However, many previous reports have focused on OVF around the thoracolumbar junction, and the surgical outcomes of lumbar OVF have not been thoroughly discussed. We aimed to investigate the surgical outcomes for lumbar OVF with a neurological deficit. Methods: Patients who underwent fusion surgery for thoracolumbar OVF with a neurological deficit were enrolled at 28 institutions. Clinical information, comorbidities, perioperative complications, Japanese Orthopaedic Association scores, visual analog scale scores, and radiographic parameters were compared between patients with lower lumbar fracture (L3-5) and those with thoracolumbar junction fracture (T10-L2). Each patient with lower lumbar fracture (L group) was matched with to patients with thoracolumbar junction fracture (T group). Results: A total 403 patients (89 males and 314 females, mean age: 73.8 ± 7.8 years, mean follow-up: 3.9 ± 1.7 years) were included in this study. Lower lumbar OVF was frequently found in patients with lower bone mineral density. After matching, mechanical failure was more frequent in the L group (L group: 64%, T group: 39%; p < 0.001). There was no difference between groups in the clinical and radiographical outcomes, although the rates of complication and revision surgery were still high in both groups. Conclusions: The surgical intervention for OVF is effective in patients with myelopathy or radiculopathy regardless of the surgical level, although further study is required to improve clinical and radiographical outcomes.

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Influence of novel design alteration of pedicle screw on pull-out strength: A finite element study

Takenaka S., Kaito T., Ishii K., Watanabe K., Watanabe K., Shinohara A., Harada T., Nakada F., Majima Y., Matsumoto M.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 25 ( 1 ) 66 - 72 2020.01

ISSN 09492658

Background: We conducted a finite element study to assess the effectiveness of a novel pedicle screw design with two alterations in the distal and proximal portions. Methods: Finite element (FE) models of 24 vertebrae were constructed using computed tomographic data. Pull-out strength of 4 different pedicle screws were compared. The basic screw design was a dual threaded one (PS0), in which the proximal portion is double-threaded (cortical thread), and the distal portion is single-threaded (cancellous thread). In PS1, the inter-thread double-core shape was added to PS0 in the distal portion. Compared to PS0, in PS2, the proximal portion was elongated by 5 mm. PS3 had both PS1 and PS2 features. In addition, the 24 vertebrae were classified into 3 groups based on volumetric bone mineral density (vBMD) of the vertebral body: low <120 mg/cm3, moderate 120–170 mg/cm3, and high >170 mg/cm3. Results: The mean pull-out strengths (±SD) were 1137 ± 500 N, 1188 ± 520 N, 1191 ± 512 N, and 1242 ± 538 N for PS0, PS1, PS2, and PS3, respectively. In PS1, there was significant difference in the incremental ratio of pull-out strength to PS0 between the low and high vBMD groups (3.7 ± 1.6% vs. 5.0 ± 1.0%, p = 0.006). In PS2, there was a significant difference in the incremental ratio to PS0 between the moderate and high vBMD groups (7.6 ± 4.0% vs. 3.3 ± 1.8%, p < 0.001). In PS3, there was a significant difference in the incremental ratio to PS0 between the moderate and high vBMD groups (12.1 ± 4.8% vs. 8.5 ± 2.1%, p = 0.003). Conclusions: The two design alterations showed the combined additive effect in the PS3 design. The moderate vBMD group has a balanced bone property to reflect the combined effects of the PS1 and PS2 design alterations.

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A comparison of cervical and thoracolumbar fractures associated with diffuse idiopathic skeletal hyperostosis—A nationwide multicenter study

Katoh H., Okada E., Yoshii T., Yamada T., Watanabe K., Katsumi K., Hiyama A., Nakagawa Y., Okada M., Endo T., Shiraishi Y., Takeuchi K., Matsunaga S., Maruo K., Sakai K., Kobayashi S., Ohba T., Wada K., Ohya J., Mori K., Tsushima M., Nishimura H., Tsuji T., Watanabe K., Matsumoto M., Okawa A., Watanabe M.

Journal of Clinical Medicine (Journal of Clinical Medicine) 9 ( 1 ) 2020.01

In diffuse idiopathic hyperostosis (DISH), the ankylosed spine becomes susceptible to spinal fractures and spinal cord injuries due to the long lever arms of the fractured segments that make the fracture extremely unstable. The aim of this retrospective multicenter study was to examine the differences in DISH-affected spine fractures according to fracture level. The data of 285 cases with fractures of DISH-ankylosed segments diagnosed through computed tomography (CT) imaging were studied and the characteristics of 84 cases with cervical fractures were compared to 201 cases with thoracolumbar fractures. Examination of the CT images revealed that cervical fracture cases were associated with ossification of the posterior longitudinal ligament and had fractures at the intervertebral disc level, while thoracolumbar fracture cases were associated with ankylosing of the posterior elements and had fractures at the vertebral body. Neurologically, cervical fracture cases had a higher ratio of spinal cord injury leading to higher mortality, while thoracolumbar fracture cases had lower rates of initial spinal cord injury. However, a subset of thoracolumbar fracture cases suffered from a delay in diagnosis that led to higher rates of delayed neurological deterioration. Some of these thoracolumbar fracture cases had no apparent injury episode but experienced severe neurological deterioration. The information provided by this study will hopefully aid in the education of patients with DISH and raise the awareness of clinicians to potential pitfalls in the assessment of DISH trauma patients.

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Impact of Tobacco Smoking on Outcomes after Posterior Decompression Surgery in Patients with Cervical Spondylotic Myelopathy: A Retrospective Multicenter Study

Nagoshi N., Kono H., Tsuji O., Aoyama R., Fujiyoshi K., Shiono Y., Ishikawa M., Daimon K., Hosogane N., Takeuchi A., Okada E., Fujita N., Yagi M., Nakamura M., Matsumoto M., Watanabe K., Ishii K., Yamane J.

Clinical Spine Surgery (Clinical Spine Surgery) 33 ( 10 ) E493 - E498 2020

ISSN 23800186

Study Design:This was a case-control study.Objective:The objective of this study was to clarify the surgical outcomes after cervical posterior decompression in patients who smoked.Summary of Background Data:Smoking is associated with poor outcomes in the field of spinal surgery. However, the impact of tobacco smoking on the outcomes after posterior decompression surgery has not been fully evaluated in patients with cervical spondylotic myelopathy.Materials and Methods:In this retrospective multicenter study, 587 patients with cervical spondylotic myelopathy were enrolled at 17 institutions in Japan. Patients underwent cervical laminoplasty or laminectomy and were followed up for at least 1 year after surgery. Outcome measures were: preoperative smoking status, perioperative complications, the Japanese Orthopedic Association scale, and the Visual Analog Scale for neck pain. After adjusting for age and sex by exact matching, smoking and nonsmoking groups were compared using an unpaired t test for continuous variables or a χ2test for categorical variables.Results:There were 182 (31%) current smokers and 405 (69%) nonsmokers including previous smokers. After matching, 158 patients were extracted from each group. Demographic data and surgical information were almost the same between the groups. Regarding postoperative complications, there was no significant difference in the rate of surgical site infection, cerebrospinal fluid leakage, hematoma, segmental motor paralysis, or neurological deficit. However, smokers showed a significantly higher risk for delirium (3.8% vs. 0.0%, P=0.039). Smokers and nonsmokers showed comparable changes in functional recovery according to Japanese Orthopedic Association scores (3.2±2.1 vs. 3.0±2.1, P=0.425) and in neck pain reduction using the Visual Analog Scale (-1.7±3.1 vs. -1.4±2.8, P=0.417) at the final follow-up.Conclusions:Smokers exhibited functional restoration and neck pain reduction after cervical posterior decompression. Attention is required, however, for the postoperative complication of delirium, which could be caused by the acute cessation of tobacco smoking after admission.Level of Evidence:Level III.

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Clinical Effects of Anterior Cervical Spondylolisthesis on Cervical Spondylotic Myelopathy After Posterior Decompression Surgery: A Retrospective Multicenter Study of 732 Cases

Ninomiya K., Yamane J., Aoyama R., Suzuki S., Shiono Y., Takahashi Y., Fujita N., Okada E., Tsuji O., Yagi M., Watanabe K., Iga T., Nakamura M., Matsumoto M., Ishii K., Nagoshi N.

Global Spine Journal (Global Spine Journal) 2020

ISSN 21925682

Study Design: Multicenter retrospective study. Objectives: We aim to investigate features of cervical spondylotic myelopathy (CSM) associated with anterior cervical spondylolisthesis (ACS) during posterior decompression surgery. Methods: A total of 732 patients with CSM were enrolled, who underwent posterior decompression surgery between July 2011 and November 2015 at 17 institutions. The patients with ACS (group A), defined as an anterior slippage of ≥2 mm on plain radiographs, were compared with those without ACS (group non-A). Also, the characteristics of patients with ACS progression (group P), defined as postoperative worsening of ACS ≥2 mm or newly developed ACS, were investigated. Moreover, kyphosis was defined as C2-C7 angle in neutral position ≤−5°. The Japanese Orthopedic Association (JOA) scoring system was used for clinical evaluation. Results: Group A consisting of 62 patients (8.5%) had worse preoperative clinical status but comparable surgical outcomes to group non-A. Furthermore, ACS was associated with greater age, and the degree of slippage did not affect myelopathy grades. Seventeen patients (2.3%) were observed in group P, and preoperative ACS was a significant predisposing factor for the progression without clinical impact. Among the patients in group A, preoperative cervical kyphosis was a risk factor for lower JOA recovery rate. Conclusions: Although the presence of ACS increases the risk of postoperative progression, it is not a contraindication for posterior decompression. However, surgeons need to consider the indication of fusion surgery for the patients who have ACS accompanied by kyphosis because of the poor surgical outcomes.

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Poor Prognostic Factors for Surgical Treatment of Spinal Intramedullary Ependymoma (World Health Organization Grade II)

Tsuji O., Nagoshi N., Ishii R., Nori S., Suzuki S., Okada E., Fujita N., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Asian Spine Journal (Asian Spine Journal) 14 ( 6 ) 821 - 828 2020

ISSN 19761902

Study Design: Single-center retrospective study. Purpose: We aimed to explore the postoperative prognostic factors for spinal intramedullary ependymoma. Overview of Literature: Ependymoma (World Health Organization grade II) is the most frequent intramedullary spinal tumor and is treated by total resection. However, postoperative deterioration of motor function occasionally occurs. Methods: Eighty patients who underwent surgical resection at Keio University and Fujita Health University in Tokyo, Japan between 2003 and 2015 with more than 2 years of follow-up were enrolled. A good surgical result was defined as an improvement in the modified McCormick Scale score by one grade or more or having the same clinical grade as was observed preoperatively. Meanwhile, a poor result was defined as a reduction in the McCormick Scale score of one grade or more or remaining in grade IV or V at final follow-up. Univariate and multivariate logistic regression analyses of the following factors were performed in the two groups: sex, age, preoperative Visual Analog Scale (VAS), tumor location, the extent of tumor resection, hemosiderin caps, cavity length, and tumor length on magnetic resonance imaging. Results: At final follow-up, 15 patients were included in the poor results group and 65 in the good results group. In the univariate analysis, the factors related to poor results were as follows: higher age, preoperative McCormick Scale score severity, higher preoperative VAS, thoracic location, hemosiderin capped, and non-gross total resection (GTR). A multiple logistic regression analysis was conducted and showed that age, worse preoperative McCormick Scale score, and non-GTR were significant factors for poor prognosis. Conclusions: The independent risk factors for motor deterioration after ependymoma resection were age, worse preoperative Mc-Cormick Scale score, and non-GTR. Early surgery for patients with even mild neurological disorders could facilitate functional outcomes. These results may contribute to determining the optimal timing of surgery for spinal intramedullary ependymoma.

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Tenosynovial giant cell tumor of the cervical spine: a case report

Furuhata R., Iwanami A., Tsuji O., Nagoshi N., Suzuki S., Okada E., Fujita N., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Spinal Cord Series and Cases (Spinal Cord Series and Cases) 5 ( 1 ) 2019.12

Introduction: Tenosynovial giant cell tumors (TSGCTs) generally occur in the limb joints, and only rarely in the spine. This case report describes a patient with TSGCT of the spine at C1–C2, which was treated surgically and diagnosed as TSGCT. Case presentation: A 32-year-old woman with a 4-month history of neck pain and numbness in both upper extremities was referred to our department. Magnetic resonance imaging (MRI) revealed a neoplastic lesion extending from the left epidural space to the erector spinae muscles at the C1–C2 vertebral level, which was isointense on T1-weighted images, heterogeneously hypointense on T2-weighted images, and showed heterogeneous enhancement on gadopentetate dimeglumine (Gd-DTPA)-enhanced T1-weighted images. Computed tomography showed no findings suggestive of bone destruction of the vertebral body. Because the neurological symptoms were progressive, total macroscopic resection of the tumor was performed via a posterior approach. Histopathological examination of the resected specimen revealed the diagnosis of TSGCT. Improvement of the both the neck pain and upper-extremity numbness was noted postoperatively. An MRI obtained 6 months after the surgery revealed no evidence of tumor recurrence and the postoperative course was uneventful. Discussion: TSGCT of the upper cervical spine (C1–C2) is rare, and this is the tenth reported case. If a tumor is heterogeneously hypointense on T2-weighted MRI, which reflects hemosiderosis, the possibility of this tumor should be considered in the differential diagnosis.

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Genome-wide association study identifies 14 previously unreported susceptibility loci for adolescent idiopathic scoliosis in Japanese

Kou I., Otomo N., Takeda K., Momozawa Y., Lu H.F., Kubo M., Kamatani Y., Ogura Y., Takahashi Y., Nakajima M., Minami S., Uno K., Kawakami N., Ito M., Yonezawa I., Watanabe K., Kaito T., Yanagida H., Taneichi H., Harimaya K., Taniguchi Y., Shigematsu H., Iida T., Demura S., Sugawara R., Fujita N., Yagi M., Okada E., Hosogane N., Kono K., Nakamura M., Chiba K., Kotani T., Sakuma T., Akazawa T., Suzuki T., Nishida K., Kakutani K., Tsuji T., Sudo H., Iwata A., Sato T., Inami S., Matsumoto M., Terao C., Watanabe K., Ikegawa S.

Nature Communications (Nature Communications) 10 ( 1 ) 2019.12

Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal deformity. Several AIS susceptibility loci have been identified; however, they could explain only a small proportion of AIS heritability. To identify additional AIS susceptibility loci, we conduct a meta-analysis of the three genome-wide association studies consisting of 79,211 Japanese individuals. We identify 20 loci significantly associated with AIS, including 14 previously not reported loci. These loci explain 4.6% of the phenotypic variance of AIS. We find 21 cis-expression quantitative trait loci-associated genes in seven of the fourteen loci. By a female meta-analysis, we identify additional three significant loci. We also find significant genetic correlations of AIS with body mass index and uric acid. The cell-type specificity analyses show the significant heritability enrichment for AIS in multiple cell-type groups, suggesting the heterogeneity of etiology and pathogenesis of AIS. Our findings provide insights into etiology and pathogenesis of AIS.

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Effects of prophylactic dexamethasone on postoperative nausea and vomiting in scoliosis correction surgery: a double-blind, randomized, placebo-controlled clinical trial

Wakamiya R., Seki H., Ideno S., Ihara N., Minoshima R., Watanabe K., Sato Y., Morisaki H.

Scientific Reports (Scientific Reports) 9 ( 1 ) 2019.12

Dexamethasone is widely used for postoperative nausea and vomiting (PONV) prophylaxis, but its effect on PONV prevention in paediatric patients is validated only in short minor surgical procedures. In this study, we aimed to determine whether a single dose of dexamethasone reduces PONV in highly invasive surgeries that require opioid-based postoperative analgesia. One hundred adolescents undergoing scoliosis correction surgery were randomized to receive intravenous dexamethasone 0.15 mg/kg (dexamethasone group) or saline (control group) at induction of anaesthesia. The primary outcome was the incidence of PONV in the 72 h postoperatively. Data for 98 patients were available for analysis. The 72-h incidence of PONV was significantly lower in the dexamethasone group than in the control group (62.5% vs 84.0%; RR 0.74, 95% CI 0.58–0.96, P = 0.02). During the first and second 24-h postoperative intervals, fewer patients in the dexamethasone group received rescue antiemetics. Visual analogue scale scores for nausea and pain were lower in the dexamethasone group than in the control group during the first 24 h postoperatively. Dexamethasone did not increase the number of adverse events. The results of this study showed that a single dose of dexamethasone was effective for reducing PONV after paediatric scoliosis correction surgery.

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Association of Susceptibility Genes for Adolescent Idiopathic Scoliosis and Intervertebral Disc Degeneration with Adult Spinal Deformity

Takeda K., Kou I., Hosogane N., Otomo N., Yagi M., Kaneko S., Kono H., Ishikawa M., Takahashi Y., Ikegami T., Nojiri K., Okada E., Funao H., Okuyama K., Tsuji T., Fujita N., Nagoshi N., Tsuji O., Ogura Y., Ishii K., Nakamura M., Matsumoto M., Ikegawa S., Watanabe K.

Spine (Spine) 44 ( 23 ) 1623 - 1629 2019.12

ISSN 03622436

Study Design.Genetic case-control study of single nucleotide polymorphisms (SNPs).Objective.To examine the association of previously reported susceptibility genes for adolescent idiopathic scoliosis (AIS) and intervertebral disc (IVD) degeneration with adult spinal deformity (ASD).Summary of Background Data.ASD is a spinal deformity that develops and progresses with age. Its etiology is unclear. Several ASD susceptibility genes were recently reported using a candidate gene approach; however, the sample sizes were small and associations with ASD development were not determined.Methods.ASD was defined as structural scoliosis with a Cobb angle more than 15° on standing radiographs, taken of patients at age 40 to 75 years in this study. Subjects in whom scoliosis was diagnosed before age 20 were excluded. We recruited 356 Japanese ASD subjects and 3341 healthy controls for case-control association studies of previously reported SNPs. We genotyped four known AIS-associated SNPs (rs11190870 in LBX1, rs6570507 in GPR126, rs10738445 in BNC2, and rs6137473 in PAX1) and three IVD degeneration-associated SNPs (rs1245582 in CHST3, rs2073711 in CILP, and rs1676486 in COL11A1) by the Invader assay.Results.Among the AIS-associated SNPs, rs11190870 and rs6137473 showed strong and nominal associations with ASD (P=1.44×10-4, 1.00×10-2, respectively). Of the IVD degeneration-associated SNPs, rs1245582 and rs2073711 showed no association with ASD, while rs1676486 showed a nominal association (P=1.10×10-2). In a subgroup analysis, rs11190870 was significantly associated with a Cobb angle more than 20° in the minor thoracic curve (P=1.44×10-4) and with a left convex lumbar curve (P=6.70×10-4), and nominally associated with an apical vertebra higher than L1 (P=1.80×10-2).Conclusion.rs11190870 in LBX1, a strong susceptibility SNP for AIS, may also be a susceptibility SNP for ASD. Thus, ASD and AIS may share a common genetic background.Level of Evidence: 4.

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An application of artificial intelligence to diagnostic imaging of spine disease: Estimating spinal alignment from moiré images

Watanabe K., Aoki Y., Matsumoto M.

Neurospine (Neurospine) 16 ( 4 ) 697 - 702 2019.12

ISSN 25866583

The use of artificial intelligence (AI) as a tool supporting the diagnosis and treatment of spinal diseases is eagerly anticipated. In the field of diagnostic imaging, the possible application of AI includes diagnostic support for diseases requiring highly specialized expertise, such as trauma in children, scoliosis, symptomatic diseases, and spinal cord tumors. Moiré topography, which describes the 3-dimensional surface of the trunk with band patterns, has been used to screen students for scoliosis, but the interpretation of the band patterns can be ambiguous. Thus, we created a scoliosis screening system that estimates spinal alignment, the Cobb angle, and vertebral rotation from moiré images. In our system, a convolutional neural network (CNN) estimates the positions of 12 thoracic and 5 lumbar vertebrae, 17 spinous processes, and the vertebral rotation angle of each vertebra. We used this information to estimate the Cobb angle. The mean absolute error (MAE) of the estimated vertebral positions was 3.6 pixels (~5.4 mm) per person. T1 and L5 had smaller MAEs than the other levels. The MAE per person between the Cobb angle measured by doctors and the estimated Cobb angle was 3.42°. The MAE was 4.38° in normal spines, 3.13° in spines with a slight deformity, and 2.74° in spines with a mild to severe deformity. The MAE of the angle of vertebral rotation was 2.9° ± 1.4°, and was smaller when the deformity was milder. The proposed method of estimating the Cobb angle and AVR from moiré images using a CNN is expected to enhance the accuracy of scoliosis screening.

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Negative impact of spinal epidural lipomatosis on the surgical outcome of posterior lumbar spinous-splitting decompression surgery: a multicenter retrospective study

Fujita N., Ishihara S., Michikawa T., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Tsuji T., Kono H., Nakamura M., Matsumoto M., Watanabe K.

Spine Journal (Spine Journal) 19 ( 12 ) 1977 - 1985 2019.12

ISSN 15299430

BACKGROUND CONTEXT: Spinal epidural lipomatosis (SEL) results from excess lumbar epidural fat (EF) accumulation that compresses the cauda equina or nerve roots. Guidelines for the therapeutic management of SEL are not currently available. PURPOSE: To elucidate the efficacy of lumbar decompression surgery in SEL. STUDY DESIGN: Multicenter retrospective study. PATIENT SAMPLE: A total of 288 consecutive patients who underwent posterior lumbar spinous-splitting decompression surgery for lumbar spinal canal stenosis and followed up greater than 2 years at participating institutions were retrospectively reviewed. OUTCOME MEASURES: Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Roland-Morris Disability Questionnaire (RDQ). METHODS: Participants were divided into two groups according to the ratio of EF to anteroposterior diameter of the spinal canal (EF/SC-L) at the spinal level with maximum dural tube compression. Patients with EF/SC-L of ≥0.6 and <0.6 were defined as those with SEL and non-SEL, respectively. We assessed whether surgical treatment was “effective” or “not effective” using the JOABPEQ based on the following: an increase of ≥20 points in the postoperative score compared with the preoperative score, or a preoperative score <90 with a postoperative score ≥90 points. We constructed a multiple Poisson regression model by adjusting for confounding factors, and determined estimated relative risk (RR) for “not effective” with surgical treatment using the JOABPEQ. Additionally, we selected age-, sex-, BMI-, and decompression levels-matched patients with non-SEL and compared the frequency of “not effective” between SEL patients (n=60) and non-SEL patients (n=60). RESULTS: Analysis using the RDQ and JOABPEQ showed that the 1- and 2-year postoperative scores were significantly better than the preoperative scores in the both groups. Multivariable Poisson regression analysis demonstrated that SEL was significantly associated with “not effective” for decompression surgery in the 1-year postoperative outcomes of walking ability ([RR] 1.5, 95% confidence interval [CI] 1.0–2.2) and social life (RR 1.3, 95% CI 1.0–1.8) and the 2-year postoperative outcomes of walking ability (RR 1.6, 95% CI 1.2–2.3). Matching analysis showed that SEL was significantly associated with “not effective” with lumbar decompression surgery in the 2-year postoperative outcomes of walking ability (p=.02). CONCLUSIONS: Patients with SEL exhibited significant improvements in surgical outcomes at 1 and 2 years postoperatively. However, compared with the non-SEL group, the efficacy of posterior lumbar spinous-splitting decompression surgery was worse in the SEL group, especially for walking ability. These results indicate that EF accumulation should be considered when planning treatment for patients with lumbar spinal canal stenosis and estimating the efficacy of lumbar decompression surgery.

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Ten-year Longitudinal Follow-up MRI Study of Age-related Changes in Thoracic Intervertebral Discs in Asymptomatic Subjects

Okada E., Daimon K., Fujiwara H., Nishiwaki Y., Nojiri K., Watanabe M., Katoh H., Ishihama H., Fujita N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 44 ( 22 ) E1317 - E1324 2019.11

ISSN 03622436

Study Design.Prospective longitudinal study.Objective.The aim of this study was to evaluate long-term degenerative changes in intervertebral discs in the thoracic spine in healthy asymptomatic subjects.Summary of Background Data.Longitudinal magnetic resonance imaging (MRI) studies of intervertebral disc degeneration have been reported for the cervical and lumbar but not the thoracic spine.Methods.In this longitudinal study (average follow-up 10.0 ± 0.6 years), we assessed degenerative changes in the thoracic spine of 103 volunteers (58 men) of 223 healthy volunteers in the initial MRI study of the thoracic spine (follow-up rate 46.2%). The mean age at the initial study was 45.0 ± 11.5 years (24-77 years). Initial and follow-up thoracic-spine MRIs were graded for the following 4 factors of degenerative changes: decrease in signal intensity of intervertebral disc (DSI), posterior disc protrusion (PDP), anterior compression of dura and spinal cord (AC), and disc-space narrowing (DSN) from T1-2 to T12-L1. We assessed associations between changes in MRI grade and demographical factors such as age, sex, body mass index, smoking habits, sports activities, and disc degeneration in the cervical spine.Results.MRIs revealed that 63.1% of the subjects had degenerative changes in the thoracic intervertebral discs that had progressed at least one grade during the follow-up period. DSI progressed in 44.7% of subjects, PDP in 21.4%, and AC in 18.4% during the 10-year period. No DSN progression was seen. DSI was frequently observed in the upper thoracic spine (T1-2 to T4-5). Disc degeneration was relatively scarce in the lower thoracic spine (T9-10 to T12-L1). PDP was frequently observed in the middle thoracic spine (T5-6 toT8-9). We found significant associations between DSI and cervical-spine degeneration (P = .004) and between AC and smoking (P = .04).Conclusion.Progressive thoracic disc degeneration, observed in 63.1% of subjects; was significantly associated with smoking and with cervical-spine degeneration.Level of Evidence: 2.

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Complications after spinal fixation surgery for osteoporotic vertebral collapse with neurological deficits: Japan Association of Spine Surgeons with ambition multicenter study

Sakai Y., Kaito T., Takenaka S., Yamashita T., Makino T., Hosogane N., Nojiri K., Suzuki S., Okada E., Watanabe K., Funao H., Isogai N., Ueda S., Hikata T., Shiono Y., Watanabe K., Katsumi K., Fujiwara H., Nagamoto Y., Terai H., Tamai K., Matsuoka Y., Suzuki H., Nishimura H., Tagami A., Yamada S., Adachi S., Ohtori S., Orita S., Furuya T., Yoshii T., Ushio S., Inoue G., Miyagi M., Saito W., Imagama S., Ando K., Sakai D., Nukaga T., Kiyasu K., Kimura A., Inoue H., Nakano A., Harimaya K., Doi T., Kawaguchi K., Yokoyama N., Oishi H., Ikegami S., Futatsugi T., Shimizu M., Kakutani K., Yurube T., Oshima M., Uei H., Aoki Y., Takahata M., Iwata A., Seki S., Murakami H., Yoshioka K., Endo H., Hongo M., Nakanishi K., Abe T., Tsukanishi T., Ishii K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 6 ) 985 - 990 2019.11

ISSN 09492658

Background: There have been few reports on the incidence and risk factors of the complications after spinal fixation surgery for osteoporotic vertebral collapse (OVC) with neurological deficits. This study aimed to identify the incidence and risk factors of the complications after OVC surgery. Methods: In this retrospective multicenter study, a total of 403 patients (314 women and 89 men; mean age 73.8 years) who underwent spinal fixation surgery for OVC with neurological deficits between 2005 and 2014 were enrolled. Data on patient demographics were collected, including age, sex, body mass index, smoking, steroid use, medical comorbidities, and surgical procedures. All postoperative complications that occurred within 6 weeks were recorded. Patients were classified into two groups, namely, complication group and no complication group, and risk factors for postoperative complications were investigated by univariate and multivariate analyses. Results: Postoperative complications occurred in 57 patients (14.1%), and the most common complication was delirium (5.7%). In the univariate analysis, the complication group was found to be older (p = 0.039) and predominantly male (p = 0.049), with higher occurrence rate of liver disease (p = 0.001) and Parkinson's disease (p = 0.039) compared with the no-complication group. In the multivariate analysis, the significant independent risk factors were age (p = 0.021; odds ratio [OR] 1.051, 95% confidence interval [CI] 1.007–1.097), liver disease (p < 0.001; OR 8.993, 95% CI 2.882–28.065), and Parkinson's disease (p = 0.009; OR 3.636, 95% CI 1.378–9.599). Conclusions: Complications after spinal fixation surgery for OVC with neurological deficits occurred in 14.1%. Age, liver disease, and Parkinson's disease were demonstrated to be independent risk factors for postoperative complications.

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Lumbar spinal canal stenosis in patients with diffuse idiopathic skeletal hyperostosis: Surgical outcomes after posterior decompression surgery without spinal instrumentation

Okada E., Yagi M., Fujita N., Suzuki S., Tsuji O., Nagoshi N., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 6 ) 999 - 1004 2019.11

ISSN 09492658

Background: To evaluate surgical outcomes after posterior decompression surgery for lumbar spinal canal stenosis (LSS) in patients with diffuse idiopathic skeletal hyperostosis (DISH). Methods: The patients (n = 184; 132 males and 52 females; mean age 72.0 years; mean follow-up 30.7 months) who underwent posterior decompression surgery for LSS were identified and classified as either DISH (D) or non-DISH (N) based on whole spine radiograph findings. Data on age, gender, American Society of Anesthesiologists (ASA) classification, operation time, and estimated blood loss, were evaluated, while radiographic parameters were measured from radiographs obtained pre- and post-operatively. Results: Mean age and ASA classification were comparable between the two groups, while the proportion of males was significantly higher in the D group (87.5%) than in the N group (67.6%) (p = 0.016). Further, mean operation time was longer in the D group (89.0 min) than in the N group (73.7 min) (p = 0.036) and mean estimated blood loss was larger in the D group (98.7 g) than in the N group (51.9 g) (p = 0.006). At two years after surgery, the development of anterior translation was significantly higher in the D group (33.3%) than in the N group (17.3%) (p = 0.021). Improvements in ODI and SF-8 after the surgery were better in the N group than in the D group. Conclusions: Compared to LSS patients without DISH who also underwent posterior decompression surgery for LSS, surgery in patients with DISH was characterized by greater blood loss, longer operation time, increased translation at the decompressed segment, and poor recovery.

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Surgical outcomes of spinal fusion for osteoporotic vertebral fracture in the thoracolumbar spine: Comprehensive evaluations of 5 typical surgical fusion techniques

Watanabe K., Katsumi K., Ohashi M., Shibuya Y., Hirano T., Endo N., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Matsuoka Y., Suzuki H., Nishimura H., Terai H., Tamai K., Tagami A., Yamada S., Adachi S., Yoshii T., Ushio S., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Kimura A., Inoue H., Inoue G., Miyagi M., Saito W., Nakano A., Sakai D., Nukaga T., Ikegami S., Shimizu M., Futatsugi T., Ohtori S., Furuya T., Orita S., Imagama S., Ando K., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Oshima M., Takahata M., Iwata A., Endo H., Abe T., Tsukanishi T., Nakanishi K., Watanabe K., Hikata T., Suzuki S., Isogai N., Okada E., Funao H., Ueda S., Shiono Y., Nojiri K., Hosogane N., Ishii K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 6 ) 1020 - 1026 2019.11

ISSN 09492658

Background: A consensus on the optimal surgical procedure for thoracolumbar OVF has yet to be reached due to the previous relatively small number of case series. The study was conducted to investigate surgical outcomes for osteoporotic vertebral fracture (OVF) in the thoracolumbar spine. Methods: In total, 315 OVF patients (mean age, 74 years; 68 men and 247 women) with neurological symptoms who underwent spinal fusion with a minimum 2-year follow-up were included. The patients were divided into 5 groups by procedure: anterior spinal fusion alone (ASF group, n = 19), anterior/posterior combined fusion (APSF group, n = 27), posterior spinal fusion alone (PSF group, n = 40), PSF with 3-column osteotomy (3CO group, n = 92), and PSF with vertebroplasty (VP + PSF group, n = 137). Results: Mean operation time was longer in the APSF group (p < 0.05), and intraoperative blood loss was lower in the VP + PSF group (p < 0.05). The amount of local kyphosis correction was greater in the APSF and 3CO groups (p < 0.05). Clinical outcomes were approximately equivalent among all groups. Conclusion: All 5 procedures resulted in acceptable neurological outcomes and functional improvement in walking ability. Moreover, they were similar with regard to complication rates, prevalence of mechanical failure related to the instrumentation, and subsequent vertebral fracture. Individual surgical techniques can be adapted to suit patient condition or severity of OVF.

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Risk, Recovery, and Clinical Impact of Neurological Complications in Adult Spinal Deformity Surgery

Yagi M., Michikawa T., Hosogane N., Fujita N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Asazuma T., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 44 ( 19 ) 1364 - 1370 2019.10

ISSN 03622436

Study Design. Multicenter retrospective case series. Objective. To report the risks, recovery, and clinical impact of neurological complications (NCs) in adult spinal deformity (ASD) surgery. Summary of Background Data. Although recent studies have reported the incidence of NCs in ASD surgery, few have addressed the recovery from and clinical impacts of NC. Methods. We reviewed records from a multicenter database for 285 consecutive surgically treated ASD patients who had reached a 2-year follow-up. NCs were categorized as sensory only or motor deficit (MD). Recovery was noted as none, partial, or complete, during hospitalization and at every postoperation visit. Uni- and multivariate risk analyses were performed to identify risk factors for MD. Results. NC developed in 29 (10%) patients within 30 days of surgery, of which 11 were permanent deficits (seven no recovery, and four partial recovery). MD developed in 14 (5%) patients, including one spinal cord injury. Seven MD patients required physical assistance at the latest follow-up. While NC patients experienced significant improvements in health-related quality of life at the 2-year follow-up, the health-related quality of life was significantly worse for the NC versus no-NC group at this time point. Univariate analyses revealed that Schwab-SRS types N and L, pelvic tilt, modified frailty index physical function, and an inferior SRS22 function domain at baseline were risk factors for MD. Among them, modified frailty index physical function, which represented a preoperative decline in activities of daily living, was identified as an independent risk factor for MD (OR: 4.0, 95% CI: 1.2-13.5, P = 0.03).Conclusions. NC developed in 10% of ASD surgery patients, with permanent deficits occurring in 4%. Half of the patients who developed MD required physical assistance, which contributed to the inferior clinical outcomes. Surgical intervention should be considered before severe activities of daily living decline to prevent NCs.

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Dietary habits had no relationship with adolescent idiopathic scoliosis: Analysis utilizing quantitative data about dietary intakes

Asakura K., Michikawa T., Takaso M., Minami S., Soshi S., Tsuji T., Okada E., Abe K., Takahashi M., Matsumoto M., Nishiwaki Y., Watanabe K.

Nutrients (Nutrients) 11 ( 10 ) 2019.10

Although several genetic and environmental factors have been identified as risk factors of adolescent idiopathic scoliosis (AIS), the influence of dietary intake has not been elucidated. We evaluated the association between AIS and dietary habits among female students. Junior high school girls aged 12 to 15 years in the Tokyo metropolitan area who underwent a second school screening for scoliosis were recruited. AIS was diagnosed by orthopedic surgeons specializing in scoliosis, using standing whole spine radiography. Students with a Cobb angle of ≥15° were classified into the AIS group, and others were considered healthy controls. Dietary assessment was performed using a validated diet history questionnaire. Dietary intakes were categorized into quintiles based on distribution, and crude and multivariable odds ratios and 95% confidence intervals for AIS for each quintile category of dietary variable were calculated, with the lowest quintile category used as a reference. In total, 2431 subjects were included in the analysis, and 47.8% of them were diagnosed with AIS. None of the selected nutrients or food groups was significantly associated with AIS. In conclusion, dietary habits may not be associated with AIS.

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The 5-Item Modified Frailty Index Is Predictive of Severe Adverse Events in Patients Undergoing Surgery for Adult Spinal Deformity

Yagi M., Michikawa T., Hosogane N., Fujita N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Asazuma T., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 44 ( 18 ) E1083 - E1091 2019.09

ISSN 03622436

Study Design.A retrospective review of 281 consecutive cases of adult spine deformity (ASD) surgery (age 55 ± 19 yrs, 91% female, follow-up 4.3 ± 1.9 yrs) from a multicenter database.Objective.To compare the value and predictive ability of the 5-item modified frailty index (mFI-5) to the conventional 11-item modified frailty index (mFI-11) for severe adverse events (SAEs).Summary of Background Data.Several recent studies have described associations between frailty and surgical complications. However, the predictive power and usefulness of the mFI-5 have not been proven.Methods.SAEs were defined as: Clavien-Dindo grade >3, reoperation required, deterioration of motor function at discharge, or new motor deficit within 2 years. The patients' frailty was categorized by the mFI-5 and mFI-11 (robust, prefrail, or frail). Spearman's rho was used to assess correlation between the mFI-5 and mFI-11. Univariate and multivariate Poisson regression analyses were conducted to analyze the relative risk of mFI-5 and mFI-11 as a predictor for SAEs in ASD surgery. Age, sex, and baseline sagittal alignment (Schwab-SRS classification subcategories) were used to adjust the baseline variance of the patients.Results.Of the 281 patients, 63 (22%) had developed SAE at 2 years. The weighted Kappa ratio between the mFI-5 and mFI-11 was 0.87, indicating excellent concordance across ASD surgery. Frailty was associated with increased total complications, perioperative complications, implant-related complications, and SAEs. Adjusted and unadjusted models showed similar c-statistics for mFI-5 and mFI-11 and a strong predictive ability for SAEs in ASD surgery. As the mFI-5 increased from 0 to ≥2, the rate of SAEs increased from 17% to 63% (P < 0.01), and the relative risk was 2.2 (95% CI: 1.3-3.7).Conclusion.The mFI-5 and the mFI-11 were equally effective predictors of SEA development in ASD surgery. The evaluation of patient frailty using mFI-5 may help surgeons optimize procedures and counsel patients.Level of Evidence: 4.

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Impact of fusion for adolescent idiopathic scoliosis on lung volume measured with computed tomography

Fujita N., Yagi M., Michikawa T., Yamada Y., Suzuki S., Tsuji O., Nagoshi N., Okada E., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

European Spine Journal (European Spine Journal) 28 ( 9 ) 2034 - 2041 2019.09

ISSN 09406719

Purpose: Although lung volume (LV) can be measured directly by computed tomography (CT), the literature regarding CT-assessed LV in adolescent idiopathic scoliosis (AIS) patients is limited, and the influence of posterior spinal fusion with instrumentation (PSF) on LV has not been established. This study aimed to identify factors associated with decreased LV after PSF in AIS patients. Methods: We retrospectively reviewed 111 consecutive AIS patients who were between 10 and 20 years of age and were treated by PSF at our facility. We assessed age at surgery, sex, height, body weight, Risser stage, Lenke classification, radiographic parameters, pulmonary function tests, and LV. Factors associated with a postoperative decrease in LV were identified by multivariable analysis. Results: The mean total LV had increased at the 2-year follow-up, although marginally significant (p =.06), and there was a significant increase in the left LV (p =.01) but not the right LV (p =.25). We observed a postoperative reduction in total LV, defined as a total LV postoperative/preoperative ratio < 0.9, in 20 of the 111 patients (18.0%). Univariable analysis showed a significant correlation between ≥ 11 fusion levels and postoperative LV reduction (OR 3.11, 95% CI 1.13–8.57). This factor remained significant in the multivariable analysis, which yielded an adjusted OR of 2.82 (95% CI 1.01–7.93) for postoperative LV reduction in patients with ≥ 11 fusion levels. Conclusion: Our data suggest that a longer fusion area is associated with postoperative LV reduction. Therefore, avoidance of a longer fusion area of ≥ 11 will be preferable for preserving LV. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].

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A review of my invention of expansive laminoplasty

Hirabayashi K., Watanabe K.

Neurospine (Neurospine) 16 ( 3 ) 379 - 382 2019.09

ISSN 25866583

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Clinical indicators of surgical outcomes after cervical single open-door laminoplasty assessed by the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire

Nagoshi N., Tsuji O., Okada E., Fujita N., Yagi M., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spinal Cord (Spinal Cord) 57 ( 8 ) 644 - 651 2019.08

ISSN 13624393

Study design: Retrospective cohort study. Objectives: The old-version JOA score for cervical myelopathy (CM) is an evaluation system performed by medical providers that focuses only on neurological function. The purpose of this study was to evaluate patient-reported outcomes using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and to clarify clinical factors that affect the therapeutic effectiveness for CM. Setting: Single institute in Japan. Methods: We reviewed surgical outcomes for 126 CM patients who were treated by single open-door laminoplasty and were followed at least 2 years. We assessed clinical information, JOACMEQ, JOA scores, and radiographic parameters. Patients were grouped according to effective or ineffective surgical outcomes as defined by the JOACMEQ using logistic regression analyses. Results: Laminoplasty resulted in functional improvement in the cervical spine and extremities for 40–50% of the patients, while bladder function showed only minimal recovery. Multivariable analyses revealed that a significant postoperative reduction in neck or shoulder pain influenced the effective functional recovery of the cervical spine. A reduction in arm or hand pain favorably affected the postoperative upper extremity function. Lower age and a postoperative decrease in limb pain were correlated with significantly improved function of the lower extremities. A postoperative reduction in arm pain enhanced the QOL recovery. Conclusions: The JOACMEQ makes it possible to analyze multiple aspects of surgical outcomes for patients who undergo cervical spine surgery. Open-door laminoplasty did not provide favorable results for some patients, which highlights the importance of assessing the indications for this procedure and managing postoperative pain.

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TBX6-associated congenital scoliosis (TACS) as a clinically distinguishable subtype of congenital scoliosis: further evidence supporting the compound inheritance and TBX6 gene dosage model

Liu J., Wu N., Yang N., Takeda K., Chen W., Li W., Du R., Liu S., Zhou Y., Zhang L., Liu Z., Zuo Y., Zhao S., Blank R., Pehlivan D., Dong S., Zhang J., Shen J., Si N., Wang Y., Liu G., Li S., Zhao Y., Zhao H., Chen Y., Zhao Y., Song X., Hu J., Lin M., Tian Y., Yuan B., Yu K., Niu Y., Yu B., Li X., Chen J., Yan Z., Zhu Q., Meng X., Chen X., Su J., Zhao X., Wang X., Ming Y., Li X., Raggio C.L., Zhang B., Weng X., Zhang S., Zhang X., Watanabe K., Matsumoto M., Jin L., Shen Y., Sobreira N.L., Posey J.E., Giampietro P.F., Valle D., Liu P., Wu Z., Ikegawa S., Lupski J.R., Zhang F., Qiu G.

Genetics in Medicine (Genetics in Medicine) 21 ( 7 ) 1548 - 1558 2019.07

ISSN 10983600

Purpose: To characterize clinically measurable endophenotypes, implicating the TBX6 compound inheritance model. Methods: Patients with congenital scoliosis (CS) from China(N = 345, cohort 1), Japan (N = 142, cohort 2), and the United States (N = 10, cohort 3) were studied. Clinically measurable endophenotypes were compared according to the TBX6 genotypes. A mouse model for Tbx6 compound inheritance (N = 52) was investigated by micro computed tomography (micro-CT). A clinical diagnostic algorithm (TACScore) was developed to assist in clinical recognition of TBX6-associated CS (TACS). Results: In cohort 1, TACS patients (N = 33) were significantly younger at onset than the remaining CS patients (P = 0.02), presented with one or more hemivertebrae/butterfly vertebrae (P = 4.9 × 10‒8), and exhibited vertebral malformations involving the lower part of the spine (T8–S5, P = 4.4 × 10‒3); observations were confirmed in two replication cohorts. Simple rib anomalies were prevalent in TACS patients (P = 3.1 × 10‒7), while intraspinal anomalies were uncommon (P = 7.0 × 10‒7). A clinically usable TACScore was developed with an area under the curve (AUC) of 0.9 (P = 1.6 × 10‒15). A Tbx6-/mh (mild-hypomorphic) mouse model supported that a gene dosage effect underlies the TACS phenotype. Conclusion: TACS is a clinically distinguishable entity with consistent clinically measurable endophenotypes. The type and distribution of vertebral column abnormalities in TBX6/Tbx6 compound inheritance implicate subtle perturbations in gene dosage as a cause of spine developmental birth defects responsible for about 10% of CS.

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A 20-year prospective longitudinal MRI study on cervical spine after whiplash injury: Follow-up of a cross-sectional study

Daimon K., Fujiwara H., Nishiwaki Y., Okada E., Nojiri K., Shimizu K., Ishihama H., Fujita N., Ichihara D., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 4 ) 579 - 583 2019.07

ISSN 09492658

Background: Some patients suffer from long-lasting symptoms after whiplash injury. However, there are few reports on the long-term changes in the cervical spine after whiplash injury using imaging tests. The purpose of this longitudinal study was to determine the changes on MRI of the cervical spine 20 years after whiplash injury, and to examine the relationships between changes in the cervical spine on MRI and changes in related clinical symptoms. Methods: Eighty-one subjects finally participated in this study (follow-up rate 16%). The mean follow-up duration was 21.7 years. All subjects filled out a questionnaire about their clinical symptoms. The MRI findings were assessed using numerical grading system applied in the original study. Statistic analyses were used to investigate whether the progression of each MRI finding was associated with the severity of neck pain, stiff shoulders, dizziness and tinnitus. Results: All subjects had complained of some clinical symptoms in the original study: 71 had neck pain, 53 stiff shoulders, and others. In the present study, 66 subjects (81.5%) complained of some clinical symptoms: 57 had stiff shoulders, 20 neck pain, and others. The progression of degeneration on MRI was observed in 95% of the subjects, with C4/5 and 5/6 being the most frequently involved levels. Changes in the severity of neck pain, stiff shoulders, dizziness and tinnitus over 20 years were not significantly associated with the progression of degenerative changes in the cervical spine on MRI. Conclusions: Twenty years after whiplash injury, 95% of the subjects showed a progression of degeneration in the cervical spine. The progression of the intervertebral disc degeneration in the cervical spine on MRI after whiplash injury was not significantly associated with changes in the severity of related clinical symptoms, indicating that the degenerative changes on MRI may reflect the physiological aging process rather than post-traumatic sequelae.

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Modic changes in the cervical spine: Prospective 20-year follow-up study in asymptomatic subjects

Tsuji T., Fujiwara H., Nishiwaki Y., Daimon K., Okada E., Nojiri K., Watanabe M., Katoh H., Shimizu K., Ishihama H., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 4 ) 612 - 617 2019.07

ISSN 09492658

Background: Few studies have characterized the development of Modic changes in the cervical spine over time. We evaluated Modic changes of the cervical spine that developed over a 20-year period in a healthy cohort, and sought to clarify the relationship between Modic changes and the development of clinical symptoms. Methods: For this multicenter prospective cohort study, we recruited 193 subjects from an original cohort of asymptomatic volunteers who underwent MRI of the cervical spine between 1993 and 1996. Each cervical level from C2/3 to C7/T1 (total n = 1158 intervertebral levels) was assessed on current MRIs as normal or showing type 1, 2, or 3 Modic change, and we asked about symptoms related to the cervical spine. Relationships between the presence of Modic changes and patient characteristics, pre-existing disc degenerations or clinical symptoms were evaluated by logistic regression analysis. Results: After 20-year follow-up, Modic changes affected 31 subjects (16.1%) at 47 intervertebral disc levels. Of these 47 intervertebral disc levels, type 2, found at 30 levels (63.8%), was the most frequent, followed by type 1 at 15 levels (31.9%) and type 3 at two levels (4.3%). The most frequent changes were observed at the C5/6 segment with type 2 Modic changes. The presence of Modic changes correlated with pre-existing posterior disc protrusion (odds ratio 3.31, 95% confidence interval 1.21–9.05) and neck pain (odds ratio 2.71, 95% confidence interval 1.08–6.80). Conclusions: In the cervical spine over a 20-year period, type 2 Modic changes were most frequent at the C5/6 segment. The Modic changes were associated with pre-existing disc degeneration and neck pain but not with age, BMI, smoking, shoulder stiffness, arm pain or numbness.

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Spinal fractures in patients with Diffuse idiopathic skeletal hyperostosis:A nationwide multi-institution survey

Okada E., Yoshii T., Yamada T., Watanabe K., Katsumi K., Hiyama A., Watanabe M., Nakagawa Y., Okada M., Endo T., Shiraishi Y., Takeuchi K., Matsunaga S., Maruo K., Sakai K., Kobayashi S., Ohba T., Wada K., Ohya J., Mori K., Tsushima M., Nishimura H., Tsuji T., Okawa A., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 4 ) 601 - 606 2019.07

ISSN 09492658

Background: Diffuse idiopathic skeletal hyperostosis (DISH) increases the spine's susceptibility to unstable fractures that can cause neurological deterioration. However, the detail of injury is still unclear. A nationwide multicenter retrospective study was conducted to assess the clinical characteristics and radiographic features of spinal fractures in patients with DISH. Methods: Patients were eligible for this study if they 1) had DISH, defined as flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies, and 2) had an injury in the ankylosing spine. This study included 285 patients with DISH (221 males, 64 females; mean age 75.2 ± 9.5 years). Results: The major cause of injury was falling from a standing or sitting position; this affected 146 patients (51.2%). Diagnosis of the fracture was delayed in 115 patients (40.4%). Later neurological deterioration by one or more Frankel grade was seen in 87 patients (30.5%). The following factors were significantly associated with neurological deficits: delayed diagnosis (p = 0.033), injury of the posterior column (p = 0.021), and the presence of ossification of the posterior longitudinal ligament (OPLL) (p < 0.001). The majority of patients (n = 241, 84.6%) were treated surgically, most commonly by conventional open posterior fixation (n = 199, 69.8%). Neurological improvement was seen in 20.0% of the conservatively treated patients, and in 47.0% of the patients treated surgically. Conclusions: Minor trauma could cause spinal fractures in DISH patients. Delayed diagnosis, injury of the posterior column, and the presence of OPLL were significantly associated with neurological deterioration. Patients with neurological deficits or unstable fractures should be treated by fixation surgery.

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Treatment for frailty does not improve complication rates in corrective surgery for adult spinal deformity

Yagi M., Michikawa T., Hosogane N., Fujita N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Asazuma T., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 44 ( 10 ) 723 - 731 2019.05

ISSN 03622436

Study Design.A retrospective multicenter database review of 240 consecutive patients at least 21 years of age (mean 58±17, range 22-79) who underwent surgery for adult spinal deformity (ASD) and were followed at least 2 years.Objective.To investigate how treatment for frailty affects complications in surgery for ASD.Summary of Background Data.Several recent studies have focused on associations between frailty and surgical complications. However, it is not clear whether treating frailty affects complication rates in surgery for ASD.Methods.Patients were categorized as robust (R group), prefrail, or frail based on the modified frailty index (mFI); prefrail and frail patients were divided by good control of frailty (G group), defined as treatment following the appropriate guidelines for each mFI factor, or poorly controlled frailty (PC group). We compared clinical outcomes and perioperative and 2-year complications between the three groups.Results.Of the 240 patients, 142 (59%) were robust, 81 (34%) were prefrail, and 17 (7%) were frail. Among the frail and prefrail patients, 71 (72%) were classified as G and 27 (28%) as PC. The perioperative complication rate was similar in the G and PC groups (32% vs. 37%) but was significantly lower in the R group (15%, P<0.01). The age-and sex-Adjusted odds ratio for 2-year complications was not different in the P group when the G group was referenced (odds ratio 1.3 [0.5-3.2], P=0.63). In the G and PC groups, which had similar 2-year outcomes, the Scoliosis Research Society-22 function and total scores were significantly lower than in the R group (function: R 3.9±0.7, G 3.5±0.7, P 3.3±0.6; total: R 3.9±0.6, 3.7±0.7, 3.4±0.6; P<0.01).Conclusion.Regardless of its treatment status, frailty increases the risk of complications and inferior clinical outcomes in ASD surgery. Surgeons should routinely evaluate frailty and inform patients of frailty-related risks when considering surgery for ASD.Level of Evidence: 4.

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A multiethnic meta-analysis defined the association of rs12946942 with severe adolescent idiopathic scoliosis

Takeda K., Kou I., Otomo N., Grauers A., Fan Y.H., Ogura Y., Takahashi Y., Momozawa Y., Einarsdottir E., Kere J., Kawakami N., Tsuji T., Uno K., Suzuki T., Ito M., Minami S., Kotani T., Sakuma T., Yanagida H., Taneichi H., Yonezawa I., Sudo H., Chiba K., Hosogane N., Nishida K., Kakutani K., Akazawa T., Kaito T., Watanabe K., Harimaya K., Taniguchi Y., Shigematsu H., Demura S., Iida T., Kono K., Okada E., Fujita N., Yagi M., Matsumoto M., Qiu Y., Song Y.Q., Gerdhem P., Watanabe K., Ikegawa S.

Journal of Human Genetics (Journal of Human Genetics) 64 ( 5 ) 493 - 498 2019.05

ISSN 14345161

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis. Controlling its curve progression is the most important clinical task. Although recent genome-wide association studies (GWASs) identified several susceptibility loci associated with the development of AIS, the etiology of curve progression has been still unknown. Our previous GWAS has identified that rs12946942 showed significant association with severe AIS. To confirm the association, we conducted an international meta-analysis using four cohorts with different ethnicity. We analyzed 2272 severe AIS cases and 13,859 controls in total, and found the replication of significant association of rs12946942 (combined P = 7.23×10 −13 ; odds ratio = 1.36, 95% confidence interval = 1.25−1.49). In silico analyses suggested that SOX9 is the most likely susceptibility gene for AIS curve progression in the locus.

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Changes in sagittal alignment after surgical excision of thoracic spinal cord tumors in adults

Kobayashi Y., Kawabata S., Nishiyama Y., Tsuji O., Okada E., Fujita N., Yagi M., Watanabe K., Matsumoto M., Nakamura M., Nagoshi N.

Spinal Cord (Spinal Cord) 57 ( 5 ) 380 - 387 2019.05

ISSN 13624393

Study design: Retrospective chart audit. Objectives: This study investigated changes in sagittal alignment in adults after excision of thoracic spinal cord tumors without spinal fixation. Setting: Single-center study at an academic orthopedic department in Japan. Methods: We retrospectively reviewed records for 32 adults who underwent excision of thoracic spinal cord tumors by multilevel laminectomies without fixation. The participants were divided according to whether the tumor was in the upper (T1–4), middle (T5–8), or lower (T9–12) thoracic spine. We analyzed parameters such as age, sex, time in surgery and estimated blood loss, follow-up period, and preoperative and follow-up the Japanese Orthopaedic Association (JOA) scores and radiographs. Results: Postoperative T1-12 kyphotic changes did not correlate with age, the number of resected laminae, or preoperative T1-12 kyphosis. JOA recovery rates were similar regardless of the tumor location. Participants with tumors in the upper thoracic spine had significant postoperative increases in T1–4 kyphosis, T1 slope (p <.05, respectively). In contrast, there were no significant changes in alignment in participants with tumors in the middle or lower thoracic spine. Conclusion: Even without fixation, sagittal alignment did not change after surgery to excise tumors in the middle and lower thoracic spine, indicating that fixation may not be necessary when excising spinal cord tumors in this region. In contrast, postoperative kyphosis may increase when the tumor is in the upper thoracic spine.

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Plate fixation of expansive open-door laminoplasty decreases the incidence of postoperative C5 palsy

Kobayashi Y., Matsumaru S., Kuramoto T., Nagoshi N., Iwanami A., Tsuji O., Okada E., Fujita N., Yagi M., Tsuji T., Ogawa J., Nakamura M., Masumoto M., Ishii K., Watanabe K.

Clinical Spine Surgery (Clinical Spine Surgery) 32 ( 4 ) E177 - E182 2019.05

ISSN 23800186

Study Design:Retrospective study.Objective:To compare outcomes for plate fixation versus suture suspension in expansive open-door laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM).Summary of Background Data:C5 palsy and laminar closure have been reported to occur after ELAP when suture suspension is used to anchor the opened lamina.Materials and Methods:We assessed 174 patients with CSM who were treated by ELAP using either suture suspension (114 patients, mean age 63.3 y, 83 men and 31 women, mean follow-up 12.0 mo) or laminoplasty plate (60 patients, mean age 65.6 y, 45 men and 15 women, mean follow-up 12.6 mo) to maintain the position of the opened laminae. We compared clinical outcomes, radiographic findings, and complications between the 2 groups.Results:Mean Japanese Orthopaedic Association scores had improved significantly for both groups at the final follow-up (P<0.001), with similar recovery rates: Scores improved from 10.8±2.8 to 13.4±2.8 points in the suture-suspension (SS) group and from 11.3±2.7 to 13.6±2.2 points in the laminoplasty plate (LP) group. The incidence of C5 palsy was significantly higher in the SS group (7.9%) than in the LP group (1.7%; P<0.05). Computed tomography (CT) showed larger mean angles of the opened laminae in the SS group compared with the LP group (P<0.01). Magnetic resonance imaging (MRI) showed that the mean anterior spinal-cord space at the C5 level was larger in the SS group than in the LP group (P<0.01).Conclusions:Plate fixation in ELAP produced comparable clinical outcomes and significantly lowered the incidence of C5 palsy compared with suture suspension. CT and MRI findings indicated that laminoplasty plate fixation prevented excessive opening of the lamina and decreased dorsal spinal-cord shift, which might explain the lower incidence of C5 palsy.

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Spinal fractures in diffuse idiopathic skeletal hyperostosis: Advantages of percutaneous pedicle screw fixation

Okada E., Shiono Y., Nishida M., Mima Y., Funao H., Shimizu K., Kato M., Fukuda K., Fujita N., Yagi M., Nagoshi N., Tsuji O., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Surgery (Journal of Orthopaedic Surgery) 27 ( 2 ) 2019.05

ISSN 10225536

Purpose: To validate the effectiveness of percutaneous pedicle screw (PPS) fixation for spinal fractures associated with diffuse idiopathic skeletal hyperostosis (DISH) by comparing surgical outcomes for PPS fixation and conventional open posterior fixation. Patients with DISH are vulnerable to unstable spinal fractures caused by trivial trauma, and these fractures have high rates of delayed paralysis, postoperative complications, and mortality. Methods: This retrospective study assessed surgical outcomes for 16 patients with DISH (12 men; mean age 76.1 ± 9.4 years) who underwent PPS fixation for spinal fractures (pedicle screw (PS) group), and for a control group of 25 patients with DISH (18 men; mean age 77.9 ± 9.9 years) who underwent conventional open fixation (O group) at our affiliated hospitals from 2007 to 2017. We evaluated the preoperative physical condition (American Society of Anesthesiologists (ASA) classification), neurological status (Frankel grade), and improvement after surgery, fusion length, operating time, estimated blood loss, and perioperative complications. Results: Preoperatively, the PS group consisted of one ASA-1 patient, eight ASA-2 patients, six ASA-3 patients, and one ASA-4 patient; by Frankel grade, there were 2 grade B patients, 13 grade C, 4 grade D, and 6 grade E patients. The O group had 2 ASA-1 patients, 13 ASA-2, 9 ASA-3, and 1 ASA-4 patients. Frankel grades in the O group reflected severe neurological deficits, with 3 grade C patients, 2 grade D, and 11 grade E (p = 0.032) patients. The two groups had similar rates of neurological improvement (33.3% of PS and 40.0% of O patients; p = 0.410) and mean fusion length (PS 5.1 ± 0.8 segments; O 4.9 ± 1.2). The mean operating time and estimated blood loss were 168.1 ± 46.7 min and 133.9 ± 116.5 g, respectively, in the PS group, and 224.6 ± 49.8 min and 499.9 ± 368.5 g in the O group. Three O-group patients died of hypovolemic shock, respiratory failure, and pneumonia, respectively, within a year of surgery. Conclusion: Conventional open posterior fixation and PPS fixation for DISH-related spinal fractures were similar in fusion length and neurological improvement. However, PPS fixation was less invasive and had lower complication rates.

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Spinal fractures in patients with diffuse idiopathic skeletal hyperostosis: Clinical characteristics by fracture level

Okada E., Shimizu K., Kato M., Fukuda K., Kaneko S., Ogawa J., Yagi M., Fujita N., Tsuji O., Suzuki S., Nagoshi N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 3 ) 393 - 399 2019.05

ISSN 09492658

© 2018 The Japanese Orthopaedic Association Background: Diffuse idiopathic skeletal hyperostosis (DISH) makes the spine prone to unstable fractures with neurological deterioration. This study was conducted to assess clinical and radiographic features of spinal fractures in DISH by the level of spinal injury, and to evaluate the optimal treatment for each level. Methods: A multicenter retrospective study over a 5-year period, including 46 patients (35 males; 11 females) with a mean age of 77.2 ± 9.7 years at the time of injury. By fracture level, there were 7 cervical (15.2%), 25 thoracic (54.3%), and 14 lumbar (30.4%) fractures. We recorded the cause of injury, whether diagnosis was delayed, and neurological status by Frankel grade. Ossification and fracture patterns were assessed by CT-multi-planar reconstruction (MPR). Results: Neurological status immediately after the cervical-spine injury was C (28.6%) or E (71.4%); after thoracic injury, C (12.0%) or E (88.0%); and after lumbar injury, D (21.4%) or E (78.6%). Inability to walk at admission was more frequent in patients with a spinal-cord injury above the lumbar level (P = .033). Vertebral-body fractures were observed in 14.3% of the cervical injuries, 80.0% of the thoracic injuries, and 50.0% of the lumbar injuries (P = .004). Most patients with a cervical fracture had a disc-level fracture (85.7%). Posterior-column ankylosis was observed in 14.3% of the cervical-fracture group, 72.0% of the thoracic-fracture group, and 78.6% of the lumbar-fracture group (P = .008). Conclusion: Ossification and fracture patterns in patients with DISH varied distinctly by the level of spinal injury. Intervertebral-disc fractures were frequently observed in the cervical spine. Delayed diagnosis, vertebral-body fracture, and posterior-column ankylosis were observed in the thoracolumbar spine. This study recommends 3 above and 3 below fusion, to avoid instrumentation failure in the fixation of spinal fracture in patients with DISH.

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Surgical risk stratification based on preoperative risk factors in adult spinal deformity

Yagi M., Hosogane N., Fujita N., Okada E., Suzuki S., Tsuji O., Nagoshi N., Asazuma T., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Spine Journal (Spine Journal) 19 ( 5 ) 816 - 826 2019.05

ISSN 15299430

© 2018 Elsevier Inc. BACKGROUND CONTEXT: Corrective surgery for adult spinal deformity (ASD) improves health-related quality of life but has high complication rates. Predicting a patient's risk of perioperative and late postoperative complications is difficult, although several potential risk factors have been reported. PURPOSE: To establish an accurate, ASD-specific model for predicting the risk of postoperative complications, based on baseline demographic, radiographic, and surgical invasiveness data in a retrospective case series. STUDY DESIGN/SETTING: Multicentered retrospective review and the surgical risk stratification. PATIENT SAMPLE: One hundred fifty-one surgically treated ASD at our hospital for risk analysis and model building and 89 surgically treated ASD at 2 other our hospitals for model validation. OUTCOME MEASURES: HRQoL measures and surgical complications. METHODS: We analyzed demographic and medical data, including complications, for 151 adults with ASD who underwent surgery at our hospital and were followed for at least 2years. Each surgical risk factor identified by univariate analyses was assigned a value based on its odds ratio, and the values of all risk factors were summed to obtain a surgical risk score (range 0–20). We stratified risk scores into grades (A–D) and analyzed their correlations with complications. We validated the model using data from 89 patients who underwent ASD surgery at two other hospitals. RESULTS: Complications developed in 48% of the patients in the model-building cohort. Univariate analyses identified 10 demographic, physical, and surgical risk indicators, with odds ratios from 5.4 to 1.4, for complications. Our risk-grading system showed good calibration and discrimination in the validation cohort. The complication rate increased with and correlated well with the risk grade using receiver operating characteristic curves. CONCLUSIONS: This simple, ASD-specific model uses readily accessible indicators to predict a patient's risk of perioperative and postoperative complications and can help surgeons adjust treatment strategies for best outcomes in high-risk patients.

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Surgical Outcomes for Drop Body Syndrome in Adult Spinal Deformity

Yagi M., Fujita N., Okada E., Tsuji O., Nagoshi N., Yato Y., Asazuma T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 44 ( 8 ) 571 - 578 2019.04

ISSN 03622436

STUDY DESIGN: A multicenter retrospective case series of patients treated surgically for adult spinal deformity (ASD). OBJECTIVE: The aim of this study was to compare clinical outcomes between propensity score matched ASD patients with or without drop body syndrome (DBS). SUMMARY OF BACKGROUND DATA: DBS is an extreme primary sagittal-plane deformity often seen in Asian countries. Although the importance of sagittal alignment is widely recognized, surgical outcomes for deformities purely in the sagittal plane are poorly understood. METHODS: This study included 243 consecutive patients (age 66 ± 17 years; range 22-78) who were treated surgically for ASD and were followed at least 2 years (mean follow-up 3.7 ± 2.3 years). DBS was defined as a primary lumbar kyphosis with PI-LL >40°, Cobb angle <30°, and multifidus cross-sectional area <300 mm. DBS patients were matched with non-DBS patients by propensity scores for age, gender, lowest instrumented vertebra (LIV) level, and number of levels fused. Demographics, radiographic findings, and clinical outcomes were compared between DBS and non-DBS patients. RESULTS: Of 243 patients with ASD, 34 had DBS (14%); 28 of these were propensity-matched with ASD patients without DBS. Baseline bone mineral density (BMD), body mass index (BMI), and frailty were similar in DBS and non-DBS patients. Baseline sagittal alignment was worse in DBS than in non-DBS patients [C7SVA 14 ± 5 vs. 8 ± 5 cm; pelvic incidence (PI) - lumbar lordosis (LL) 60 ± 14 vs. 36 ± 20°], and scoliosis research society (SRS)22 scores were also worse for DBS patients (2.5 ± 0.6 vs. 2.9 ± 0.8). Although DBS patients had more complications (20 DBS vs. 16 non-DBS), the clinical outcomes were similarly improved in both groups after surgery. At the 2-year follow-up, the spinopelvic malalignment was worse in DBS than non-DBS patients (PI-LL 17 ± 16° vs. 8 ± 13°, P < 0.05). CONCLUSION: DBS affected 14% of 234 ASD patients. Although DBS patients had inferior baseline SRS22 scores than non-DBS patients, ASD surgery resulted in similar clinical improvement in both groups. Future studies should examine the influence of lifestyle and genetics on clinical outcomes after surgery for DBS.3.

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Potential involvement of semaphorin 3A in maintaining intervertebral disc tissue homeostasis

Mima Y., Suzuki S., Fujii T., Morikawa T., Tamaki S., Takubo K., Shimoda M., Miyamoto T., Watanabe K., Matsumoto M., Nakamura M., Fujita N.

Journal of Orthopaedic Research (Journal of Orthopaedic Research) 37 ( 4 ) 972 - 980 2019.04

ISSN 07360266

© 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. Intervertebral discs (IVDs) are avascular; however, ingrowth of blood vessels into their outer regions has been noted during the progression of degeneration. The mechanisms underlying vascularization in IVD degeneration are not completely understood. Semaphorin 3A (Sema3A), originally characterized as a chemorepulsive factor for growing axons in the developing nervous system, inhibits angiogenesis. This study aimed to elucidate the potential involvement of Sema3A in maintaining tissue homeostasis within the avascular IVD. We demonstrated that the mRNA expression of Sema3A was higher in rat annulus fibrosus (AF) than in nucleus pulposus (NP) and that its expression level decreased with age. Both mRNA and protein expression level of Sema3A was also markedly suppressed in AF tissues of a rat IVD degeneration model. Both real-time RT-PCR and Western blot clearly indicated that Sema3A expression significantly reduced by treating inflammatory cytokines in rat AF cells. In a gain- and loss-of-function study, we observed that Sema3A reduced the catabolic shift in rat AF cells. In addition, our results indicated that Sema3A potentially inhibited the IL-6/JAK/STAT pathway. Finally, BrdU assay and tube formation assay revealed that treatment of recombinant Sema3A significantly blocks both proliferation and tube formation of HUVEC. Our results indicate that Sema3A may help maintain IVD tissue homeostasis. Thus, although further studies are needed, Sema3A may be a potential molecular target for suppressing IVD degeneration. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

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Surgical outcomes of spinal fusion for osteoporotic thoracolumbar vertebral fractures in patients with Parkinson's disease: What is the impact of Parkinson's disease on surgical outcome?

Watanabe K., Katsumi K., Ohashi M., Shibuya Y., Izumi T., Hirano T., Endo N., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Matsuoka Y., Suzuki H., Nishimura H., Terai H., Tamai K., Tagami A., Yamada S., Adachi S., Yoshii T., Ushio S., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Kimura A., Inoue H., Inoue G., Miyagi M., Saito W., Nakano A., Sakai D., Nukaga T., Ikegami S., Shimizu M., Futatsugi T., Ohtori S., Furuya T., Orita S., Imagama S., Ando K., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Oshima M., Takahata M., Iwata A., Endo H., Abe T., Tsukanishi T., Nakanishi K., Watanabe K., Hikata T., Suzuki S., Isogai N., Okada E., Funao H., Ueda S., Shiono Y., Nojiri K., Hosogane N., Ishii K.

BMC Musculoskeletal Disorders (BMC Musculoskeletal Disorders) 20 ( 1 ) 2019.03

Background: To date, there have been little published data on surgical outcomes for patients with PD with thoracolumbar OVF. We conducted a retrospective multicenter study of registry data to investigate the outcomes of fusion surgery for patients with Parkinson's disease (PD) with osteoporotic vertebral fracture (OVF) in the thoracolumbar junction. Methods: Retrospectively registered data were collected from 27 universities and their affiliated hospitals in Japan. In total, 26 patients with PD (mean age, 76 years; 3 men and 23 women) with thoracolumbar OVF who underwent spinal fusion with a minimum of 2 years of follow-up were included (PD group). Surgical invasion, perioperative complications, radiographic sagittal alignment, mechanical failure (MF) related to instrumentation, and clinical outcomes were evaluated. A control group of 296 non-PD patients (non-PD group) matched for age, sex, distribution of surgical procedures, number of fused segments, and follow-up period were used for comparison. Results: The PD group showed higher rates of perioperative complications (p < 0.01) and frequency of delirium than the non-PD group (p < 0.01). There were no significant differences in the degree of kyphosis correction, frequency of MF, visual analog scale of the symptoms, and improvement according to the Japanese Orthopaedic Association scoring system between the two groups. However, the PD group showed a higher proportion of non-ambulators and dependent ambulators with walkers at the final follow-up (p < 0.01). Conclusions: A similar surgical strategy can be applicable to patients with PD with OVF in the thoracolumbar junction. However, physicians should pay extra attention to intensive perioperative care to prevent various adverse events and implement a rehabilitation regimen to regain walking ability.

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Spinal correction surgery improves asymmetrical trunk kinematics during gait in adolescent idiopathic scoliosis with thoracic major curve

Nishida M., Nagura T., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

European Spine Journal (European Spine Journal) 28 ( 3 ) 619 - 626 2019.03

ISSN 09406719

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: To clarify the effect of posterior correction and fusion surgery on the trunk–pelvic kinematics during gait in adolescent idiopathic scoliosis (AIS) patients with single thoracic major curve. Methods: Among preoperative AIS patients who planned correction surgery, 18 patients with Lenke type 1A or B were selected for this study. All patients were female. The patients’ trunk and pelvic kinematics during gait were measured three-dimensionally and dynamically using reflective markers, optoelectronic motion capture system. The gait analysis was performed before and 1–2 years after surgery. The trunk and pelvic symmetry during gait was evaluated at coronal, sagittal, and transverse planes between concave and convex sides. Results: The trunk and pelvic angles in sagittal and coronal planes were equivalent between concave and convex sides before and after surgery. Preoperatively, transverse trunk rotation angles were significantly deviated toward the concave (left) side during both static standing (4.3 ± 2.0°) and gait (8.8 ± 0.6°, p < 0.01). Preoperative transverse pelvic rotation angles were significantly deviated toward the convex side during static standing (4.0 ± 3.8°). However, pelvis displayed with symmetric rotational kinematics during gait. Postoperatively, the deviated transverse trunk rotation angle significantly decreased (1.6 ± 0.3°), and the transverse rotational kinematics of both trunk and pelvis improved to symmetric. Conclusions: Posterior correction and fusion surgery have improved preoperative asymmetric global rotational kinematics of trunk and pelvis in transverse plane to symmetric postoperatively in AIS patients with thoracic single major curve. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].

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Identification of novel LFNG mutations in spondylocostal dysostosis

Otomo N., Mizumoto S., Lu H., Takeda K., Campos-Xavier B., Mittaz-Crettol L., Guo L., Takikawa K., Nakamura M., Yamada S., Matsumoto M., Watanabe K., Ikegawa S.

Journal of Human Genetics (Journal of Human Genetics) 64 ( 3 ) 261 - 264 2019.03

ISSN 14345161

Spondylocostal dysostosis (SCDO) is a heterogeneous group of skeletal disorders characterized by multiple segmentation defects involving vertebrae and ribs. Seven disease genes have been reported as causal genes for SCDO: DLL3, MESP2, TBX6, HES7, RIPPLY2, DMRT2, and LFNG. Here we report a Japanese SCDO case with multiple severe vertebral anomalies from cervical to sacral spine. The patient was a compound heterozygote for c.372delG (p.K124Nfs*) and c.601G>A (p.D201N) variants of LFNG, which encodes a glycosyltransferase (O-fucosylpeptide 3-beta-N-acetylglucosaminyltransferase). The missense variant was in the DxD motif, an active-site motif of the glycosyltransferase, and its loss of the enzyme function was confirmed by an in vitro enzyme assay. This is the second report of LFNG mutations in SCDO.

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Spinal epidural lipomatosis is a previously unrecognized manifestation of metabolic syndrome

Ishihara S., Fujita N., Azuma K., Michikawa T., Yagi M., Tsuji T., Takayama M., Matsumoto H., Nakamura M., Matsumoto M., Watanabe K.

Spine Journal (Spine Journal) 19 ( 3 ) 493 - 500 2019.03

ISSN 15299430

© 2018 Elsevier Inc. BACKGROUND CONTEXT: Spinal epidural lipomatosis (SEL) is a condition in which excess lumbar epidural fat (EF) deposition often leads to compression of the cauda equina or nerve root. Although SEL is often observed in obese adults, no systematic research investigating the potential association between SEL and metabolic syndrome has been conducted. PURPOSE: To elucidate potential association between SEL and metabolic syndrome. STUDY DESIGN: An observational study used data of a medical checkup. PATIENT SAMPLE: We retrospectively reviewed data from consecutive subjects undergoing medical checkups. A total of 324 subjects (174 men and 150 women) were enrolled in this study. OUTCOME MEASURES: The correlation of EF accumulation with demographic data and metabolic-related factors was evaluated. METHODS: The degree of EF accumulation was evaluated based on the axial views of lumbar magnetic resonance imaging. Visceral and subcutaneous fat areas were measured at the navel level using abdominal computed tomography. Metabolic syndrome was diagnosed according to the criteria of the Japanese Society of Internal Medicine. The correlation of SEL with metabolic syndrome and metabolic-related conditions was statistically evaluated. RESULTS: The degree of EF accumulation demonstrated a significant correlation to body mass index, abdominal circumference, and visceral fat area. However, age, body fat percentage, and subcutaneous fat area showed no correlation with the degree of EF accumulation. Logistic regression analysis revealed that metabolic syndrome (odds ratio [OR]=3.8, 95% confidence interval [CI]=1.5–9.6) was significantly associated with SEL. Among the diagnostic criteria for metabolic syndrome, visceral fat area ≥100 cm 2 (OR=4.8, 95% CI=1.5–15.3) and hypertension (OR=3.5, 95% CI=1.1–11.8) were observed to be independently associated with SEL. CONCLUSION: This is the first study to demonstrate that metabolic syndrome is associated with SEL in a relatively large, unbiased population. Our data suggest that metabolic-related conditions are potentially related to EF deposition and that SEL could be a previously unrecognized manifestation of metabolic syndrome.

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Myelopathy due to human T-cell leukemia virus type-1 from the donor after ABO-incompatible liver transplantation

Wakabayashi T., Obara H., Seki M., Shinoda M., Kitago M., Yagi H., Abe Y., Matsubara K., Yamada Y., Oshima G., Oki K., Nagoshi N., Watanabe K., Hibi T., Itano O., Hoshino K., Suzuki N., Kuroda T., Kitagawa Y.

Annals of Hepatology (Annals of Hepatology) 18 ( 2 ) 397 - 401 2019.03

ISSN 16652681

We report the case of a 53-year-old-man who developed human T-cell leukemia virus type-1-associated myelopathy (HAM) after ABO-incompatible liver transplantation for alcoholic liver cirrhosis. The living donor was seropositive for human T-cell leukemia virus type-1 (HTLV-1) and the recipient was seronegative for HTLV-1 before transplantation. After transplantation, the recipient developed steroid-resistant acute cellular rejection, which was successfully treated using anti-thymocyte globulin, and he was eventually discharged. He underwent spinal surgery twice after the transplantation for the treatment of cervical spondylosis that had been present for a period of 9 months before the transplantation. The surgery improved his gait impairment temporarily. However, his gait impairment progressed, and magnetic resonance imaging revealed multiple sites of myelopathy. He was diagnosed with HAM 16 months after the transplantation. Pulse steroid therapy (1000 mg) was administered over a period of 3 days, and his limb paresis improved. Presently, steroid therapy is being continued, with a plan to eventually taper the dose, and he is being carefully followed up at our institution. Our case suggests that liver transplantation involving an HTLV-1-positive living donor carries the risk of virus transmission and short-term development of HAM after transplantation.

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Does Posterior Cervical Decompression Conducted by Junior Surgeons Affect Clinical Outcomes in the Treatment of Cervical Spondylotic Myelopathy? Results From a Multicenter Study

Nagoshi N., Iwanami A., Isogai N., Ishikawa M., Nojiri K., Tsuji T., Daimon K., Takeuchi A., Tsuji O., Okada E., Fujita N., Yagi M., Watanabe K., Nakamura M., Matsumoto M., Ishii K., Yamane J.

Global Spine Journal (Global Spine Journal) 9 ( 1 ) 25 - 31 2019.02

ISSN 21925682

© The Author(s) 2018. Study Design: Retrospective multicenter study. Objectives: To evaluate the outcomes of posterior cervical decompression for cervical spondylotic myelopathy (CSM) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. Methods: We reviewed outcomes for 675 patients who underwent surgery for CSM, were followed at least 1 year after surgery, and were assessed preoperatively and at final follow-up by Japanese Orthopaedic Association (JOA) scores and by the visual analog scale (VAS) for the neck. Cervical alignment was assessed on radiographs by C2-C7 angles, and range of motion (ROM) by extension minus flexion C2-C7 angles. We compared outcomes for BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and for NBCS surgeons. Results: BCS surgeons performed 432 of 675 laminoplasties. NBCS surgeons were primary in 243 surgeries, of which 187 were directly supervised by a BCS surgeon. BCS surgeons required significantly less time in surgery (98.0 ± 39.5 vs 108.1 ± 49.7 min; P <.01). BCS and NBCS surgeons had comparable perioperative complications rates, and preoperative-to-postoperative changes in JOA scores (2.9 ± 2.1 vs 3.1 ± 2.3; P =.40) and VAS (−1.5 ± 2.9 vs −1.4 ± 2.5; P =.96). Lordotic cervical alignment and ROM were maintained after operations by both groups. Conclusions: Surgical outcomes such as functional recovery, complication rates, and cervical dynamics were comparable between the BCS and NBCS groups. Thus, posterior cervical decompression for CSM is safe and effective when performed by junior surgeons who have been trained and supervised by experienced spine surgeons.

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Impact of lumbar hypolordosis on the incidence of symptomatic postoperative spinal epidural hematoma after decompression surgery for lumbar spinal canal stenosis

Fujita N., Michikawa T., Yagi M., Suzuki S., Tsuji O., Nagoshi N., Okada E., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

European Spine Journal (European Spine Journal) 28 ( 1 ) 87 - 93 2019.01

ISSN 09406719

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: Potential associations between radiographic parameters and the incidence of symptomatic postoperative spinal epidural hematoma (PSEH) have not been identified. This study aimed to identify risk factors including radiographic parameters for symptomatic PSEH after posterior decompression surgery for lumbar spinal canal stenosis (LSS). Methods: We retrospectively reviewed 1007 consecutive patients who underwent lumbar decompression surgery for lumbar spinal canal stenosis (LSS) at our institution. We identified 35 cases of symptomatic PSEH, defined by clinical symptoms and MRI findings, and selected 3 or 4 age- and sex-matched control subjects for each PSEH subject (124 controls). We compared radiographic parameters and previously reported risk factors between PSEH and control subjects. Results: Compared to the control group, PSEH patients had significantly higher preoperative systolic (p =.020) and diastolic (p =.048) blood pressure, and more levels of decompression (p =.001). PSEH and control subjects had significant differences in lumbar lordosis (PSEH 24.8° ± 14.6°, control 34.8° ± 14.5°), pelvic tilt (25.1° ± 11.7° vs. 20.8° ± 8.4°), sacral slope (23.4° ± 9.4° vs. 27.6° ± 8.3°), and pelvic incidence minus lumbar lordosis (23.7° ± 15.0° vs. 13.7° ± 14.6°). Multivariate analysis revealed two significant risk factors for PSEH: decompression of two or more levels and lumbar lordosis < 25°. Conclusions: Multilevel decompression and hypolordosis are significant risk factors for symptomatic PSEH after decompression surgery for LSS. LSS patients with lumbar hypolordosis or multilevel stenosis should be carefully observed for PSEH after decompression surgery. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].

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Predictive model for major complications 2 years after corrective spine surgery for adult spinal deformity

Yagi M., Hosogane N., Fujita N., Okada E., Tsuji O., Nagoshi N., Asazuma T., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

European Spine Journal (European Spine Journal) 28 ( 1 ) 180 - 187 2019.01

ISSN 09406719

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: ASD surgery improves a patient’s health-related quality of life, but it has a high complication rate. The aim of this study was to create a predictive model for complications after surgical treatment for adult spinal deformity (ASD), using spinal alignment, demographic data, and surgical invasiveness. Methods: This study included 195 surgically treated ASD patients who were > 50 years old and had 2-year follow-up from multicenter database. Variables which included age, gender, BMI, BMD, frailty, fusion level, UIV and LIV, primary or revision surgery, pedicle subtraction osteotomy, spinal alignment, Schwab-SRS type, surgical time, and blood loss were recorded and analyzed at least 2 years after surgery. Decision-making trees for 2-year postoperative complications were constructed and validated by a 7:3 data split for training and testing. External validation was performed for 25 ASD patients who had surgery at a different hospital. Results: Complications developed in 48% of the training samples. Almost half of the complications developed in late post-op period, and implant-related complications were the most common complication at 2 years after surgery. Univariate analyses showed that BMD, frailty, PSO, LIV, PI-LL, and EBL were risk factors for complications. Multivariate analysis showed that low BMD, PI-LL > 30°, and frailty were independent risk factors for complications. In the testing samples, our predictive model was 92% accurate with an area under the receiver operating characteristic curve of 0.963 and 84% accurate in the external validation. Conclusion: A successful model was developed for predicting surgical complications. Our model could inform physicians about the risk of complications in ASD patients in the 2-year postoperative period. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].

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Acute Paraparesis Due to Protrusion of a Disc Following Lateral Interbody Fusion for Degenerative Kyphoscoliosis: A Case Report

Ruchirawan S., Fujita N., Yagi M., Tsuji O., Okada E., Nagoshi N., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

JBJS case connector (JBJS case connector) 9 ( 1 ) 1 - 5 2019.01

ISSN 21603251

CASE: A 74-year-old woman presented with severe trunk deformity. Radiographs revealed severe sagittal and coronal imbalance with spinal canal stenosis at L4 to L5. Anterior cages were placed at L2 to L3, L3 to L4, and L4 to L5. Three days later, posterior correction surgery from T5 to the ilium with decompression at L4 to L5 was performed. At 30 minutes after surgery, leg muscle strength severely deteriorated. Emergency surgery revealed disc fragments protruding into the spinal canal at L2 to L3. CONCLUSION: Because posteriorly placed extreme lateral interbody fusion (XLIF) cages can be a risk factor for disc protrusion into the spinal canal, computed tomographic evaluation or prophylactic posterior decompression should be considered before the correction procedure.

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Early surgical intervention may facilitate recovery of cervical spinal cord injury in DISH

Tsuji O., Suda K., Takahata M., Matsumoto-Harmon S., Komatsu M., Menjo Y., Watanabe K., Ishii K., Nakamura M., Matsumoto M., Minami A., Iwasaki N.

Journal of Orthopaedic Surgery (Journal of Orthopaedic Surgery) 27 ( 1 ) 2019.01

ISSN 10225536

© The Author(s) 2019. Study design: A retrospective study of consecutive surgically managed cases of cervical spinal fractures and diffuse idiopathic skeletal hyperostosis (DISH) at our hospital from October 2006 to April 2016. Summary of background data: Prognostic factors have not been determined for cervical fractures in DISH. Objectives: To assess demographics, surgical techniques, and complications in cervical spinal cord injury with DISH and to evaluate factors affecting neurological prognosis. Methods: Patients’ medical records and radiographs were reviewed and analyzed for demographics, injury characteristics, surgical outcomes, perioperative complications, additional surgeries, and neurological prognosis. Neurological status was assessed by the American Spinal Injury Association (ASIA) grade at admission and discharge. Results: Of 38 patients (mean age 71.9 ± 8.8), 20 had type 1 fractures (through the disc space), 8 had type 2 (through the vertebral body), and 10 had type 3 (through disc and vertebral body). ASIA grades at admission included 14 ASIA-A, 4 ASIA-B, 7 ASIA-C, 8 ASIA-D, and 5 ASIA-E. All patients underwent posterior fusion with an average of 4.5 ± 2.5 instrumented vertebrae (range, 2–7) and six patients required secondary halo-vest fixation. Of 14 ASIA-A patients, 12 developed serious postsurgical pulmonary complications and 4 of these died within 6 months of surgery. Of the 38 patients, 13 improved more than one grade after treatment, 24 did not improve, and 1 deteriorated. In the 18 ASIA-A/B cases (complete motor paralysis), neither fracture type nor injury mechanism (e.g. a ground-level fall or high-energy trauma) correlated with neurological prognosis, but a time of 8 h or less from injury to surgery correlated significantly with an improvement from ASIA A/B to C/D (p < 0.01, Pearson’s χ 2 test). Conclusion: Patients with complete motor paralysis after a cervical fracture with DISH may recover to partial paralysis if surgically treated within 8 h of injury.

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Lumbar spinal canal stenosis leads to locomotive syndrome in elderly patients

Fujita N., Sakurai A., Miyamoto A., Michikawa T., Tsuji O., Nagoshi N., Okada E., Yagi M., Otaka Y., Tsuji T., Kono H., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 1 ) 19 - 23 2019.01

ISSN 09492658

© 2018 The Japanese Orthopaedic Association Background: Locomotive syndrome is a condition in which the ability to lead a normal life is restricted owing to a dysfunction in one or more of the parts of the musculoskeletal system. Although lumbar spinal canal stenosis (LSS) is considered to cause locomotive syndrome, a detailed assessment of the association between two pathologies has not yet been reported. Methods: The clinical data of patients aged > 65 years old who planned to undergo surgery for LSS at multiple institutions were prospectively collected from April 2016 to August 2017. A total of 200 participants comprising 120 men and 80 women were enrolled in this study. Association of severity of LSS evaluated by Zurich Claudication Questionnaire scores with three locomotive syndrome risk tests (Stand-up Test, the Two-step Test, and a 25-question risk assessment) and Timed Up-and-Go Test were evaluated. Results: In the total assessment of locomotive syndrome, 96.5% of the participants were diagnosed as grade 2, and the remaining 3.5% were diagnosed as grade 1. When the participants were divided into 3 groups according to the LSS severity, the scores of all locomotive syndrome risk tests were significantly worse with increasing LSS severity. Logistic regression analysis revealed that LSS severity was positively correlated with the risk level of locomotive syndrome evaluated by the Two-step Test (OR = 3.45, CI = 1.33–8.96). Conclusions: All LSS patients with surgical indications were diagnosed as having locomotive syndrome. In addition, our results indicated that LSS severity is potentially associated with the progression of locomotive syndrome. The treatment of LSS may be beneficial in alleviating the risk for locomotive syndrome.

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Surgical treatment of osteoporotic vertebral fracture with neurological deficit - A nationwide multicenter study in Japan

Hosogane N., Nojiri K., Suzuki S., Funao H., Okada E., Isogai N., Ueda S., Hikata T., Shiono Y., Watanabe K., Watanabe K., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Terai H., Tamai K., Matsuoka Y., Suzuki H., Nishimura H., Tagami A., Yamada S., Adachi S., Ohtori S., Orita S., Furuya T., Yoshii T., Ushio S., Inoue G., Miyagi M., Saito W., Imagama S., Ando K., Sakai D., Nukaga T., Kiyasu K., Kimura A., Inoue H., Nakano A., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Ikegami S., Shimizu M., Futatsugi T., Kakutani K., Yurube T., Oshima M., Uei H., Aoki Y., Takahata M., Iwata A., Seki S., Murakami H., Yoshioka K., Endo H., Hongo M., Nakanishi K., Abe T., Tsukanishi T., Ishii K.

Spine Surgery and Related Research (Spine Surgery and Related Research) 3 ( 4 ) 361 - 367 2019

Introduction: The prevalence of patients with osteoporosis continues to increase in aging societies, including Japan. The first choice for managing osteoporotic vertebral compression fracture (OVF) is conservative treatment. Failure in conservative treatment for OVF may lead to non-union or vertebral collapse, resulting in neurological deficit and subsequently requiring surgical intervention. This multicenter nationwide study in Japan was conducted to comprehensively understand the outcomes of surgical treatments for OVF non-union. Methods: This multicenter, retrospective study included 403 patients (89 males, 314 females, mean age 73.8 ± 7.8 years, mean follow-up 3.9 ± 1.7 years) with neurological deficit due to vertebral collapse or non-union after OVF at T10-L5 who underwent fusion surgery with a minimum 1-year follow-up. Radiological and clinical outcomes at baseline and at the final follow-up (FU) were evaluated. Results: OVF was present at a thoracolumbar junction such as T12 (124 patients) and L1 (117 patients). A majority of OVF occurred after a minor trauma, such as falling down (55.3%) or lifting objects (8.4%). Short segment fusion, including affected vertebra, was conducted (mean 4.0 ± 2.0 vertebrae) with 256.8 minutes of surgery and 676.1 g of blood loss. A posterior approach was employed in 86.6% of the patients, followed by a combined anterior and posterior (8.7%), and an anterior (4.7%) approach. Perioperative complications and implant failures were observed in 18.1% and 41.2%, respectively. VAS scores of low back pain (74.7 to 30.8 mm) and leg pain (56.8 to 20.7 mm) improved significantly at FU. Preoperatively, 52.6% of the patients were unable to walk and the rate of non-ambulatory patients decreased to 7.5% at FU. Conclusions: This study demonstrated that substantial improvement in activity of daily living (ADL) was achieved by fusion surgery. Although there was a considerable rate of complications, fusion surgery is beneficial for elderly OVF patients with non-union.

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Stride length of elderly patients with lumbar spinal stenosis: Multi-center study using the Two-Step test

Fujita N., Sakurai A., Miyamoto A., Michikawa T., Otaka Y., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Tsuji T., Kono H., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 24 ( 5 ) 787 - 792 2019

ISSN 09492658

© 2019 Background: Short stride length is one of clinical symptoms associated with lumbar spinal stenosis (LSS). Short stride is a risk factor for falls; therefore, identification of factors associated with short stride is critical for fall prevention in LSS patients. Although the Two-Step test can conveniently assess maximal stride length, it has not become widely used; therefore, its data are limited. We identified the potential factors associated with short stride of elderly LSS patients using Two-Step test. Methods: Clinical data of patients aged >65 years who planned to undergo surgery for LSS were prospectively collected at multiple institutions. Patients were assessed with the Two-Step test and Timed Up-and-Go Test prior to surgery; 357 consecutive patients were enrolled. We determined the cut-off value of the Two-Step test score for short stride, referring to the Timed Up-and-Go Test score of 13.5 s, used to indicate high risk of falls in elderly individuals. Logistic regression model was constructed to identify factors associated with short stride. Results: The Two-Step test score showed moderate-to-strong inverse correlation with that of Timed Up-and-Go Test (r = −0.65, p < 0.001). Using the tentative Two-Step test cut-off value (0.93) for short stride, multivariable analysis showed that age ≥80 years (OR = 2.3, 95% CI:1.1–4.8), a score of <60 for lumbar function in Japanese Orthopedic Association Back Pain Evaluation Questionnaire (OR = 2.7, 95% CI:1.5–4.7), motor deficit (OR = 2.7, 95% CI:1.2–6.1), and sagittal vertical axis ≥50 mm (OR = 2.1, 95% CI:1.2–3.5) were factors significantly associated with short stride in elderly patients with LSS. Conclusions: Using the Two-Step test, we found that 80 years old and over, lumbar dysfunction, motor deficit of the lower extremities, and forward-bent posture were associated with short stride in LSS patients. Therefore, elderly LSS patients with these conditions may have a higher risk for falls.

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Lumbar spinal surgery improves locomotive syndrome in elderly patients with lumbar spinal canal stenosis: A multicenter prospective study

Fujita N., Michikawa T., Miyamoto A., Sakurai A., Otaka Y., Suzuki S., Tsuji O., Nagoshi N., Okada E., Yagi M., Tsuji T., Kono H., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 25 ( 2 ) 213 - 218 2019

ISSN 09492658

© 2019 The Japanese Orthopaedic Association Background: Owing to musculoskeletal dysfunction, locomotive syndrome elevates the risk of requiring nursing care. Among degenerative musculoskeletal disorders, lumbar spinal canal stenosis (LSS) associates with locomotive syndrome; however, whether lumbar spinal surgery for LSS improves locomotive syndrome remains unclear. Hence, this study aimed to identify the efficacy of lumbar spinal surgery on locomotive syndrome among elderly patients with LSS. Methods: We prospectively collected the clinical data from multiple institutions of patients (age >65 years) who underwent lumbar spinal surgery. Patients were examined for the locomotive syndrome risk test, including the stand-up Test, the two-step Test, and the 25-question risk assessment, 1-day preoperatively and 6-month and 1-year postoperatively. Using a logistic regression model, we identified factors associated with improvement of locomotive syndrome in the total assessment. Results: Overall, we examined the data of 166 patients in this study. Upon converting each score of three tests to the stage of locomotive syndrome, the two-step test and the 25-question risk assessment revealed marked improvement in the postoperative distribution of stages. However, the stand-up test revealed a comparable distribution of stages pre- and postoperatively. In the total assessment, the postoperative distribution of stages was significantly improved than that preoperatively. The multivariable analysis revealed that failed back surgery syndrome [odds ratio (OR), 0.2; 95% confidence interval (CI): 0.04–1.05; P = 0.057)] and preoperative stage of 2 in stand-up test (OR, 0.2; 95% CI: 0.05–1.02; P = 0.054) tended to have inverse association with postoperative improvement of locomotive syndrome in the total assessment. Conclusions: Lumbar spinal surgery improved the stage of locomotive syndrome among elderly patients with LSS. This study suggests that lumbar spinal surgery for LSS could be beneficial in alleviating locomotive syndrome.

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Bi-allelic loss of function variants of TBX6 causes a spectrum of malformation of spine and rib including congenital scoliosis and spondylocostal dysostosis

Otomo N., Takeda K., Kawai S., Kou I., Guo L., Osawa M., Alev C., Kawakami N., Miyake N., Matsumoto N., Yasuhiko Y., Kotani T., Suzuki T., Uno K., Sudo H., Inami S., Taneichi H., Shigematsu H., Watanabe K., Yonezawa I., Sugawara R., Taniguchi Y., Minami S., Kaneko K., Nakamura M., Matsumoto M., Toguchida J., Watanabe K., Ikegawa S.

Journal of Medical Genetics (Journal of Medical Genetics) 56 ( 9 ) 622 - 628 2019

ISSN 00222593

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ. Background: Congenital scoliosis (CS) is a common vertebral malformation. Spondylocostal dysostosis (SCD) is a rare skeletal dysplasia characterised by multiple vertebral malformations and rib anomalies. In a previous study, a compound heterozygosity for a null mutation and a risk haplotype composed by three single-nucleotide polymorphisms in TBX6 have been reported as a disease-causing model of CS. Another study identified bi-allelic missense variants in a SCD patient. The purpose of our study is to identify TBX6 variants in CS and SCD and examine their pathogenicity. Methods: We recruited 200 patients with CS or SCD and investigated TBX6 variants. We evaluated the pathogenicity of the variants by in silico prediction and in vitro experiments. Results: We identified five 16p11.2 deletions, one splice-site variant and five missense variants in 10 patients. In vitro functional assays for missense variants identified in the previous and present studies demonstrated that most of the variants caused abnormal localisation of TBX6 proteins. We confirmed mislocalisation of TBX6 proteins in presomitic mesoderm cells induced from SCD patient-derived iPS cells. In induced cells, we found decreased mRNA expressions of TBX6 and its downstream genes were involved in somite formation. All CS patients with missense variants had the risk haplotype in the opposite allele, while a SCD patient with bi-allelic missense variants did not have the haplotype. Conclusions: Our study suggests that bi-allelic loss of function variants of TBX6 cause a spectrum of phenotypes including CS and SCD, depending on the severity of the loss of TBX6 function.

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Clinical outcomes and prognostic factors for cavernous hemangiomas of the spinal cord: A retrospective cohort study

Nagoshi N., Tsuji O., Nakashima D., Takeuchi A., Kameyama K., Okada E., Fujita N., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Journal of Neurosurgery: Spine (Journal of Neurosurgery: Spine) 31 ( 2 ) 271 - 278 2019

ISSN 15475654

OBJECTIVE Intramedullary cavernous hemangioma (CH) is a rare vascular lesion that is mainly characterized by the sudden onset of hemorrhage in young, asymptomatic patients, who then experience serious neurological deterioration. Despite the severity of this condition, the therapeutic approach and timing of intervention for CH remain matters of debate. The aim of this study was to evaluate the clinical characteristics of CH patients before and after surgery and to identify prognostic indicators that affect neurological function in these patients. METHODS This single-center retrospective study included 66 patients who were treated for intramedullary CH. Among them, 57 underwent surgery and 9 patients received conservative treatment. The authors collected demographic, symptomology, imaging, neurological, and surgical data. Univariate and multivariate logistic regression analyses were performed to identify the prognostic indicators for neurological function. RESULTS When comparing patients with stable and unstable gait prior to surgery, patients with unstable gait had a higher frequency of hemorrhagic episodes (52.4% vs 19.4%, p = 0.010), as assessed by the modified McCormick Scale. The lesion was significantly smaller in patients who underwent conservative treatment compared with surgery (2.5 ± 1.5 mm vs 5.9 ± 4.1 mm, respectively; p = 0.024). Overall, the patients experienced significant neurological recovery after surgery, but a worse preoperative neurological status was identified as an indicator affecting surgical outcomes by multivariate analysis (OR 10.77, 95% CI 2.88–40.36, p < 0.001). In addition, a larger lesion size was significantly associated with poor functional recovery in patients who had an unstable gait prior to surgery (8.6 ± 4.5 mm vs 3.5 ± 1.6 mm, p = 0.011). CONCLUSIONS Once a hemorrhage occurs, surgical intervention should be considered to avoid recurrence of the bleeding and further neurological injury. In contrast, if the patients with larger lesion presented with worse preoperative functional status, surgical intervention could have a risk for aggravating the functional deficiencies by damaging the thinning cord parenchyma. Conservative treatment may be selected if the lesion is small, but regular neurological examination by MRI is needed for assessment of a change in lesion size and for detection of functional deterioration.

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Risk factors for proximal junctional fracture following fusion surgery for osteoporotic vertebral collapse with delayed neurological deficits: A retrospective cohort study of 403 patients

Tamai K., Terai H., Suzuki A., Nakamura H., Watanabe K., Katsumi K., Ohashi M., Shibuya Y., Izumi T., Hirano T., Kaito T., Yamashita T., Fujiwara H., Nagamoto Y., Matsuoka Y., Suzuki H., Nishimura H., Tagami A., Yamada S., Adachi S., Yoshii T., Ushio S., Harimaya K., Kawaguchi K., Yokoyama N., Oishi H., Doi T., Kimura A., Inoue H., Inoue G., Miyagi M., Saito W., Nakano A., Sakai D., Nukaga T., Ikegami S., Shimizu M., Futatsugi T., Ohtori S., Furuya T., Orita S., Imagama S., Ando K., Kobayashi K., Kiyasu K., Murakami H., Yoshioka K., Seki S., Hongo M., Kakutani K., Yurube T., Aoki Y., Oshima M., Takahata M., Iwata A., Endo H., Abe T., Tsukanishi T., Nakanishi K., Watanabe K., Hikata T., Suzuki S., Isogai N., Okada E., Funao H., Ueda S., Shiono Y., Nojiri K., Hosogane N., Ishii K.

Spine Surgery and Related Research (Spine Surgery and Related Research) 3 ( 2 ) 171 - 177 2019

Introduction: Approximately 3% of osteoporotic vertebral fractures develop osteoporotic vertebral collapse (OVC) with neurological deficits, and such patients are recommended to be treated surgically. However, a proximal junctional fracture (PJFr) following surgery for OVC can be a serious concern. Therefore, the aim of this study is to identify the incidence and risk factors of PJFr following fusion surgery for OVC. Methods: This study retrospectively analyzed registry data collected from facilities belonging to the Japan Association of Spine Surgeons with Ambition (JASA) in 2016. We retrospectively analyzed 403 patients who suffered neurological deficits due to OVC below T10 and underwent corrective surgery; only those followed up for !2 years were included. Potential risk factors related to the PJFr and their cut-off values were calculated using multivariate logistic regression analysis and receiver operating characteristic (ROC) analysis. Results: Sixty-three patients (15.6%) suffered PJFr during the follow-up (mean 45.7 months). In multivariate analysis, the grade of osteoporosis (grade 2, 3: adjusted odds ratio (aOR) 2.92; p=0.001) and lower instrumented vertebra (LIV) level (sacrum: aOR 6.75; p=0.003) were independent factors. ROC analysis demonstrated that lumbar bone mineral density (BMD) was a predictive factor (area under curve: 0.72, p=0.035) with optimal cut-off value of 0.61 g/cm2 (sensitivity, 76.5%; specificity, 58.3%), but that of the hip was not (p=0.228). Conclusions: PJFr was found in 16% cases within 4 years after surgery; independent risk factors were severe osteoporosis and extended fusion to the sacrum. The lumbar BMD with cut-off value 0.61 g/cm2 may potentially predict PJFr. Our findings can help surgeons select perioperative adjuvant therapy, as well as a surgical strategy to prevent PJFr following surgery.

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Surgical Treatment of Cervical Spondylotic Myelopathy in the Elderly: Outcomes in Patients Aged 80 Years or Older

Isogai N., Nagoshi N., Iwanami A., Kono H., Kobayashi Y., Tsuji T., Fujita N., Yagi M., Watanabe K., Kitamura K., Shiono Y., Nakamura M., Matsumoto M., Ishii K., Yamane J.

Spine (Spine) 43 ( 24 ) E1430 - E1436 2018.12

ISSN 03622436

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: We aimed to assess the outcomes following posterior cervical decompression for cervical spondylotic myelopathy (CSM) in a large sample of patients older than 80 years. SUMMARY OF BACKGROUND DATA: Although age is a predictor of surgical outcomes for CSM, most previous studies have only investigated the effect of age for patients aged 65 to 75 years, and surgical outcomes remain unclear for older patients. METHODS: Patients older than 50 years who underwent posterior cervical decompression for CSM were enrolled from 17 institutions. The patients were grouped into a young-old group (<80 yrs old) and an old-old group (≥80 yrs). Clinical information, comorbidities, perioperative complications, Japanese Orthopaedic Association (JOA) scores, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), visual analog scale (VAS) scores, and radiographic parameters were compared between the two groups. All patients were followed for at least 1 year after surgery. RESULTS: The young-old and old-old groups included 491 and 77 patients, respectively. The JOA score and quality of life measured by JOACMEQ improved significantly after surgery in both groups. Compared with the young-old group, the old-old group had lower preoperative JOA scores (9.6 vs. 11.0), lower final JOA scores (12.6 vs. 14.0), and lower recovery rates (42% vs. 50%). However, there were no significant differences in perioperative complications or in the VAS scores at the final assessments. The old-old group had a higher mean preoperative sagittal Cobb angle at C2-C5, though this was not statistically significant postoperatively. CONCLUSION: Posterior decompression surgery is safe and beneficial for patients older than 80 years with CSM, despite having a more limited neurological recovery compared with younger patients.3.

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A multi-ethnic meta-analysis confirms the association of rs6570507 with adolescent idiopathic scoliosis

Kou I., Watanabe K., Takahashi Y., Momozawa Y., Khanshour A., Grauers A., Zhou H., Liu G., Fan Y., Takeda K., Ogura Y., Zhou T., Iwasaki Y., Kubo M., Wu Z., Matsumoto M., Kawakami N., Uno K., Suzuki T., Sudo H., Minami S., Kotani T., Ito M., Yanagida H., Taneichi H., Yonezawa I., Chiba K., Hosogane N., Fujita N., Yagi M., Kono K., Okada E., Nishida K., Kakutani K., Sakuma T., Harimaya K., Kaito T., Watanabe K., Taniguchi Y., Tsuji T., Akazawa T., Karol L., Rathjen K., Sucato D., Birch J., Johnston C., Richards B., Ramo B., McIntosh A., Herring J., Einarsdottir E., Kere J., Huang D., Qiu G., Qiu Y., Wise C., Song Y., Wu N., Su P., Gerdhem P., Ikegawa S.

Scientific Reports (Scientific Reports) 8 ( 1 ) 2018.12

© 2018, The Author(s). Adolescent idiopathic scoliosis (AIS) is the most common type of spinal deformity and has a significant genetic background. Genome-wide association studies (GWASs) identified several susceptibility loci associated with AIS. Among them is a locus on chromosome 6q24.1 that we identified by a GWAS in a Japanese cohort. The locus is represented by rs6570507 located within GPR126. To ensure the association of rs6570507 with AIS, we conducted a meta-analysis using eight cohorts from East Asia, Northern Europe and USA. The analysis included a total of 6,873 cases and 38,916 controls and yielded significant association (combined P = 2.95 × 10 −20 ; odds ratio = 1.22), providing convincing evidence of the worldwide association between rs6570507 and AIS susceptibility. In silico analyses strongly suggested that GPR126 is a susceptibility gene at this locus.

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Twenty-year Longitudinal Follow-up MRI Study of Asymptomatic Volunteers the Impact of Cervical Alignment on Disk Degeneration

Okada E., Daimon K., Fujiwara H., Nishiwaki Y., Nojiri K., Watanabe M., Katoh H., Shimizu K., Ishihama H., Fujita N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Clinical Spine Surgery (Clinical Spine Surgery) 31 ( 10 ) 446 - 451 2018.12

ISSN 23800186

© 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design: A 20-year longitudinal study. Objective: To evaluate the long-term effect of sagittal alignment of the cervical spine on intervertebral disk degeneration in healthy asymptomatic subjects. Summary of Background Data: This study continues a previous 10-year longitudinal study to determine whether sagittal alignment affects disk degeneration during normal aging. Materials and Methods: We assessed 90 healthy subjects (30 men and 60 women) from among 497 volunteers who underwent magnetic resonance imaging (MRI) and plain radiographs of the cervical spine between 1994 and 1996 (follow-up rate 18.1%). The mean age at the initial study was 35.5 13.4 years (11-65 y). We compared initial MRIs and follow-up MRIs, conducted at an average of 21.6 years after the initial study, for (1) decreased signal intensity of the intervertebral disks, (2) posterior disk protrusion, and (3) disk-space narrowing from C2-3 to C7-T1. Subjects were grouped by age at follow-up (under 40 vs. 40 y and older) and by a lordotic or nonlordotic cervical sagittal alignment at baseline. We assessed neck pain, stiff shoulders, and upper-arm numbness at follow-up, and examined associations between clinical symptoms and MRI parameters. Results: Progressive changes during the 20-year period included a decrease in disk signal intensity (84.4% of subjects), posterior disk protrusion (86.7%), and disk-space narrowing (17.8%). No significant association was observed between sagittal alignment and decreased disk signal intensity, posterior disk protrusion, or disk-space narrowing. Among subjects over the age of 40, progressive degenerative changes at C7-T1 were significantly more frequent in nonlordotic subjects (90.9%) compared with those with cervical lordosis (54.2%, P= 0.032). The prevalence of clinical symptoms was similar in lordotic and nonlordotic subjects at follow-up. Conclusions: Nonlordotic cervical alignment was related to the progression of disk degeneration at C7-T1 but not other levels. Cervical alignment did not affect the development of clinical symptoms in healthy subjects.

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Perioperative Complications After Surgery for Thoracic Ossification of Posterior Longitudinal Ligament: A Nationwide Multicenter Prospective Study

Imagama S., Ando K., Takeuchi K., Kato S., Murakami H., Aizawa T., Ozawa H., Hasegawa T., Matsuyama Y., Koda M., Yamazaki M., Chikuda H., Shindo S., Nakagawa Y., Kimura A., Takeshita K., Wada K., Katoh H., Watanabe M., Yamada K., Furuya T., Tsuji T., Fujibayashi S., Mori K., Kawaguchi Y., Watanabe K., Matsumoto M., Yoshii T., Okawa A.

Spine (Spine) 43 ( 23 ) E1389 - E1397 2018.12

ISSN 03622436

STUDY DESIGN: Prospective, multicenter, nationwide study. OBJECTIVE: To investigate perioperative complications and risk factors in surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) using data from the registry of the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. SUMMARY OF BACKGROUND DATA: There is no prospective multicenter study of surgical complications and risk factors for T-OPLL, and previous multicenter retrospective studies have lacked details. METHODS: Surgical methods, preoperative radiographic findings, pre- and postoperative thoracic myelopathy (Japanese Orthopaedic Association [JOA] score), prone and supine position test (PST), intraoperative ultrasonography, and intraoperative neurophysiological monitoring (IONM) were investigated prospectively in 115 cases (males: 55, females: 60, average age 53.1 y). Factors related to perioperative complications and risk factors for postoperative motor palsy were identified. RESULTS: Posterior decompression and fusion with instrumentation with or without dekyphosis was performed in 85 cases (74%). The JOA recovery rate at 1 year after surgery in all cases was 55%. Motor palsy occurred postoperatively in 37 cases (32.2%), with a mean recovery period of 2.7 months. A long recovery period for postoperative motor palsy was significantly associated with a high number of T-OPLL levels (P < 0.0001), lower preoperative JOA score (P < 0.05), and greater estimated blood loss (P < 0.05). Perioperative complications or postoperative motor palsy were significantly related to a higher number of T-OPLL levels, comorbid ossification of ligamentum flavum rate, lower preoperative JOA score, higher preoperative positive PST rate, more surgical invasiveness, a lower rate of intraoperative spinal cord floating in ultrasonography, and higher rate of deterioration of IONM. CONCLUSION: This study firstly demonstrated the perioperative complications with high postoperative motor palsy rate in a nationwide multicenter prospective study. Surgical outcomes for T-OPLL should be improved by identifying and preventing perioperative complications with significant risk factors.3.

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Imaging Comparison Between Chinese and Japanese Patients With Cervical Ossification of the Posterior Longitudinal Ligament

Xiao B., Nagoshi N., Takeuchi A., Mao J., Liu B., Tian W., Tsuji O., Okada E., Fujita N., Yagi M., Nakamura M., Matsumoto M., Ishii K., Watanabe K.

Spine (Spine) 43 ( 23 ) E1376 - E1383 2018.12

ISSN 03622436

STUDY DESIGN: A retrospective study. OBJECTIVE: To identify the radiographic differences between Chinese and Japanese patients with cervical ossification of the posterior longitudinal ligament (OPLL) using computed tomography (CT) and magnetic resonance imaging (MRI), and to compare the characteristics of OPLL between the two nationalities. SUMMARY OF BACKGROUND DATA: OPLL has a high prevalence in East Asia. However, the differences between Chinese and Japanese OPLL patients are poorly known. METHODS: This was a retrospective study of Chinese (n = 300) and Japanese (n = 102) consecutive patients who received a diagnosis of cervical OPLL between January 2010 and December 2014. All patients underwent CT and MRI. The type and distribution of OPLL were determined. Spinal compression was assessed by MRI. OPLL type, distribution, comorbidity, and compression of the spinal cord were examined. The ossification index (OP-index) was used to evaluate the OPLL. Factors contributing to the OP-index were examined by multivariate analysis. RESULTS: The Chinese patients were younger than the Japanese patients (P < 0.0001), and there were more women among the Chinese patients (P = 0.0002). The OP-index was higher among the Japanese patients (median, 5 vs. 4, P = 0.003). Among men, OPLL lesions were more frequent in the under 55-year-old Japanese at C7 (P = 0.04), in the 55 to 64-year-old Japanese at C4, C5, and C6 (all P < 0.05), and in the over 64-year-old Japanese at C3/4 (P = 0.01), compared with their Chinese counterparts. Among women, OPLL lesions were more frequent in the 55 to 64-year-old Japanese at C6 (P = 0.04). The multivariate analysis showed that only age was independently associated with the OP-index (odds ratio [OR] = 1.023, 95% confidence interval [CI]: 1.002-1.045, P = 0.034). CONCLUSION: Japanese patients had a higher frequency of OPLL lesions at C5, C6, and C7. Age was independently associated with OPLL.3.

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An international meta-analysis confirms the association of BNC2 with adolescent idiopathic scoliosis

Ogura Y., Takeda K., Kou I., Khanshour A., Grauers A., Zhou H., Liu G., Fan Y., Zhou T., Wu Z., Takahashi Y., Matsumoto M., Kawakami N., Tsuji T., Uno K., Suzuki T., Ito M., Minami S., Kotani T., Sakuma T., Yanagida H., Taneichi H., Yonezawa I., Sudo H., Chiba K., Hosogane N., Nishida K., Kakutani K., Akazawa T., Kaito T., Watanabe K., Harimaya K., Taniguchi Y., Shigematsu H., Demura S., Iida T., Kono K., Okada E., Fujita N., Yagi M., Nakamura M., Karol L., Rathjen K., Sucato D., Birch J., Johnston C., Richards B., Ramo B., McIntosh A., Herring J., Milbrandt T., Talwakar V., Iwinski H., Muchow R., Tassone J., Liu X., Shindell R., Schrader W., Eberson C., Lapinsky A., Loder R., Davey J., Einarsdottir E., Kere J., Huang D., Qiu G., Xu L., Qiu Y., Wise C., Song Y., Wu N., Su P., Gerdhem P., Watanabe K., Ikegawa S.

Scientific Reports (Scientific Reports) 8 ( 1 ) 2018.12

© 2018 The Author(s). Adolescent idiopathic scoliosis (AIS) is a common spinal deformity with the prevalence of approximately 3%. We previously conducted a genome-wide association study (GWAS) using a Japanese cohort and identified a novel locus on chromosome 9p22.2. However, a replication study using multi-population cohorts has not been conducted. To confirm the association of 9p22.2 locus with AIS in multi-ethnic populations, we conducted international meta-Analysis using eight cohorts. In total, we analyzed 8,756 cases and 27,822 controls. The analysis showed a convincing evidence of association between rs3904778 and AIS. Seven out of eight cohorts had significant P value, and remaining one cohort also had the same trend as the seven. The combined P was 3.28 × 10 -18 (odds ratio = 1.19, 95% confidence interval = 1.14-1.24). In silico analyses suggested that BNC2 is the AIS susceptibility gene in this locus.

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Genome-wide meta-analysis and replication studies in multiple ethnicities identify novel adolescent idiopathic scoliosis susceptibility loci

Khanshour A., Kou I., Fan Y., Einarsdottir E., Makki N., Kidane Y., Kere J., Grauers A., Johnson T., Paria N., Patel C., Singhania R., Kamiya N., Takeda K., Otomo N., Watanabe K., Luk K., Cheung K., Herring J., Rios J., Ahituv N., Gerdhem P., Gurnett C., Song Y., Ikegawa S., Wise C.

Human Molecular Genetics (Human Molecular Genetics) 27 ( 22 ) 3986 - 3998 2018.11

ISSN 09646906

© The Author(s) 2018. Published by Oxford University Press. All rights reserved. Adolescent idiopathic scoliosis (AIS) is the most common musculoskeletal disorder of childhood development. The genetic architecture of AIS is complex, and the great majority of risk factors are undiscovered. To identify new AIS susceptibility loci, we conducted the first genome-wide meta-analysis of AIS genome-wide association studies, including 7956 cases and 88 459 controls from 3 ancestral groups. Three novel loci that surpassed genome-wide significance were uncovered in intragenic regions of the CDH13 (P-value_rs4513093 = 1.7E-15), ABO (P-value_ rs687621 = 7.3E-10) and SOX6 (P-value_ rs1455114 = 2.98E-08) genes. Restricting the analysis to females improved the associations at multiple loci, most notably with variants within CDH13 despite the reduction in sample size. Genome-wide gene-functional enrichment analysis identified significant perturbation of pathways involving cartilage and connective tissue development. Expression of both SOX6 and CDH13 was detected in cartilage chondrocytes and chromatin immunoprecipitation sequencing experiments in that tissue revealed multiple HeK27ac-positive peaks overlapping associated loci. Our results further define the genetic architecture of AIS and highlight the importance of vertebral cartilage development in its pathogenesis.

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Prevalence and Distribution of Diffuse Idiopathic Skeletal Hyperostosis on Whole-spine Computed Tomography in Patients with Cervical Ossification of the Posterior Longitudinal Ligament

Nishimura S., Nagoshi N., Iwanami A., Takeuchi A., Hirai T., Yoshii T., Takeuchi K., Mori K., Yamada T., Seki S., Tsuji T., Fujiyoshi K., Furukawa M., Wada K., Koda M., Furuya T., Matsuyama Y., Hasegawa T., Takeshita K., Kimura A., Abematsu M., Haro H., Ohba T., Watanabe M., Katoh H., Watanabe K., Ozawa H., Kanno H., Imagama S., Ando K., Fujibayashi S., Yamazaki M., Watanabe K., Matsumoto M., Nakamura M., Okawa A., Kawaguchi Y.

Clinical Spine Surgery (Clinical Spine Surgery) 31 ( 9 ) E460 - E465 2018.11

ISSN 23800186

© 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design: This was a retrospective multicenter study. Objective: To clarify the progression of diffuse idiopathic skeletal hyperostosis (DISH) using whole-spine computed tomography in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Summary of Background Data: DISH and cervical OPLL frequently coexist, and can cause ankylosing spinal fractures due to biomechanical changes and fragility of the affected vertebrae. The epidemiology and pathophysiology of DISH occurring with cervical OPLL are unclear. Materials and Methods: We used whole-spine computed tomography to determine the prevalence of DISH in 234 patients with a diagnosis of cervical OPLL based on plain cervical radiographs. We established a novel system for grading the progression of DISH based on a cluster analysis of the DISH distribution along the spine. We calculated the correlation coefficient between this grading system and patient age. Results: The prevalence of DISH in patients with cervical OPLL was 48.7%. Patients with DISH were significantly older than those who did not have DISH (67.3 vs. 63.4 y; P=0.005). Cluster analysis classified the DISH distribution into 6 regions, based on the levels affected: C2-C5, C3-T1, C6-T5, T3-10, T8-L2, and T12-S1. DISH was observed most frequently at T3-T10. We defined a system for grading DISH progression based on the number of regions involved, from grade 0 to 6. DISH was distributed at T3-T10 in >60% of the grade 1 patients, whereas most patients with DISH at the cervical or lumbar spine were grade 4 or 5. There was a weak but significant correlation between the DISH grade and patient age. Conclusions: DISH was present in nearly half of the patients with cervical OPLL. DISH was more common in older patients. DISH developed at the thoracic level and progressed into the cervical and/or lumbar spine with age. Level of Evidence: Level III.

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Metabolite profiling of plasma in patients with ossification of the posterior longitudinal ligament

Tsuji T., Matsumoto M., Nakamura M., Miyamoto T., Yagi M., Fujita N., Okada E., Nagoshi N., Tsuji O., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 23 ( 6 ) 878 - 883 2018.11

ISSN 09492658

© 2018 The Japanese Orthopaedic Association Background: Metabolomics is one of the “omics” technologies, and is a comprehensive analysis of small molecule metabolites which include amino acid, nucleotides, carbohydrates and fatty acid. The purpose of the present study was to compare the differences of metabolite profiling between patients with ossification of the posterior longitudinal ligament (OPLL) and control subjects. Methods: We analyzed plasma metabolites in patients with cervical OPLL (n = 10) and in control subjects (n = 10). Ionic metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) and lipophilic metabolites were analyzed using liquid chromatograph time-of-flight mass spectrometry (LC-TOFMS). Results: A total of 259 metabolites (144 metabolites in CE-TOFMS and 115 metabolites in LC-TOFMS) were detected. Among the 259 metabolites, six metabolites, namely acylcarnitine (AC) (14:0), palmitoylcarnitine, AC (18:2), fatty acid (FA) (24:2), thyroxine, thiaproline were significantly larger in OPLL group, even in analyzes excluding patients with diabetes mellitus and hyperlipidemia. Conclusions: We examined the metabolite profiling in patients with OPLL for the first time and detected six metabolites showing suggestive association with disease. These results of the present study could lead to new insights into clarifying the molecular pathomechanisms of OPLL.

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Screening of known disease genes in congenital scoliosis

Takeda K., Kou I., Mizumoto S., Yamada S., Kawakami N., Nakajima M., Otomo N., Ogura Y., Miyake N., Matsumoto N., Kotani T., Sudo H., Yonezawa I., Uno K., Taneichi H., Watanabe K., Shigematsu H., Sugawara R., Taniguchi Y., Minami S., Nakamura M., Matsumoto M., Watanabe K., Ikegawa S.

Molecular Genetics and Genomic Medicine (Molecular Genetics and Genomic Medicine) 6 ( 6 ) 966 - 974 2018.11

© 2018 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc. Background: Congenital scoliosis (CS) is defined as a lateral curvature of the spine due to the vertebral malformations and has an incidence of 0.5–1/1,000 births. We previously examined TBX6 in Japanese CS patients and revealed that approximately 10% of CS was caused by TBX6 mutations. However, the genetic cause of remaining CS is unknown. Methods: We recruited 78 CS patients without TBX6 mutations and major comorbidities, and investigated the genes previously reported to be associated with CS and congenital vertebral malformations by whole-exome sequencing. Results: We identified the compound heterozygous missense variants in LFNG in one patient. No likely disease-causing variants were identified in other patients, however. LFNG encodes a GlcNAc-transferase. The LFNG variants showed loss of their enzyme function. Conclusions: A LFNG mutation is reported in a case of spondylocostal dysostosis (SCD), a skeletal dysplasia with severe malformations of vertebra and rib. The CS patient with LFNG mutations had multiple vertebral malformations including hemivertebrae, butterfly vertebrae, and block vertebrae, and rib malformations. LFNG mutations may cause a spectrum of phenotypes including CS and SCD. The current list of known disease genes could explain only a small fraction of genetic cause of CS.

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Modic changes and disc degeneration in adolescent idiopathic scoliosis patients who reach middle age without surgery: Can residual deformity cause lumbar spine degeneration?

Akazawa T., Watanabe K., Matsumoto M., Tsuji T., Kawakami N., Kotani T., Sakuma T., Yamamoto T., Demura S., Orita S., Fujimoto K., Shiga Y., Niki H.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 23 ( 6 ) 884 - 888 2018.11

ISSN 09492658

© 2018 The Japanese Orthopaedic Association Background: We have yet to determine what types of lumbar degenerative changes can be observed on MRI in middle-aged adolescent idiopathic scoliosis (AIS) patients without undergoing surgery. The aims of this study were to investigate AIS patients who have reached middle age without undergoing surgery and to clarify if residual spinal deformities may have affected health-related quality of life (HRQOL) and lumbar spine degeneration. Methods: Subjects comprised AIS patients who reached middle age without surgery and who underwent whole-spine X-rays, lumbar MRI, and SRS-22 surveys. Of the 60 cases collected from five scoliosis centers, 25 patients who met the inclusion criteria were enrolled into the residual deformity (RD) group and analyzed. Controls (CTR) group comprised 25 individuals matched for age, sex, and BMI with the patient group. Results: MRI revealed no significant differences in the percentage of individuals with Pfirrmann grade 4 or 5 disc degeneration in 1 or more segments (RD group: 84%, CTR group: 60%, p = 0.059). Significantly more patients with Modic changes in 1 or more segments were observed in the RD group (RD group: 56%, CTR group: 8%, p < 0.001). All SRS-22 scores were significantly lower in the RD group. The lumbar curve cutoff point based on whether or not Modic change could be observed using ROC analysis was 39.5°. Conclusions: Compared to healthy individuals, AIS patients with residual deformity who have never had surgery showed similar prevalence of disc degeneration, but they had more Modic changes and poor HRQOL. The cutoff point for lumbar curves of patients with and without Modic changes in middle age was 39.5°.

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Impact of Frailty and Comorbidities on Surgical Outcomes and Complications in Adult Spinal Disorders

Yagi M., Fujita N., Okada E., Tsuji O., Nagoshi N., Tsuji T., Asazuma T., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 43 ( 18 ) 1259 - 1267 2018.09

ISSN 03622436

STUDY DESIGN: Retrospective review of surgically treated 481 adult patients with spinal disorders. OBJECTIVE: The aim of this study was to elucidate the effect of frailty and comorbidities on postoperative health-related quality of life (HRQoL) and complication rates. SUMMARY OF BACKGROUND DATA: Elective surgeries for spinal disorders not only improve clinical outcomes but also have high complication rates. METHODS: We retrospectively reviewed the results of consecutive elective spine surgeries for 156 adult spinal deformities (ASDs: 65 ± 9 years), 152 degenerative spondylolisthesis (DS: 64 ± 10 years), or 173 lumbar spinal canal stenosis (LSCS: 71 ± 9 years) with follow-up of at least 2 years. Modified Frailty Index (mFI) and Charlson Comorbidity Index (CCI) were determined from baseline demographics. We compared the prevalence and the influence of mFI and CCI on postoperative outcomes and complication rates. RESULTS: The mFI and CCI were significantly worse in ASD than in others (mFI: ASD 0.09 ± 0.12, DS 0.06 ± 0.06, LSCS 0.04 ± 0.05, P < 0.01. CCI: ASD 2.1 ± 1.6, DS 1.4 ± 0.7, LSCS 1.6 ± 0.9, P < 0.01). Postoperative HRQoL deteriorated as mFI worsened in ASD (nofrail: Oswestry Disability Index [ODI] 26 ± 11, Scoliosis Research Society Questionnaire [SRS] 3.7 ± 0.7; prefrail: ODI 32 ± 12, SRS 3.6 ± 0.6; frail: ODI 42 ± 15, SRS 3.2 ± 0.7). In DS and LSCS, however, SF-36 physical component score and mental component score improved regardless of mFI and CCI. The 2-year major complications rate increased with frailty (36%, 58%, and 81%) in ASD, but not in others. CONCLUSION: ASDs were more frail and had more comorbidities than the other populations. In ASD, postsurgical outcomes and complication rates deteriorated as frailty and CCI increased, whereas surgery produced favorable outcomes and acceptable complication rates in DS and LSCS regardless of frailty and CCI. Careful patient selection and treatment of comorbidities before surgery may decrease complications and improve outcomes for the surgical treatment of ASD.4.

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Postoperative pain management in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis: A narrative review

Seki H., Ideno S., Ishihara T., Watanabe K., Matsumoto M., Morisaki H.

Scoliosis and Spinal Disorders (Scoliosis and Spinal Disorders) 13 ( 1 ) 2018.09

© 2018 The Author(s). Posterior spinal fusion for adolescent idiopathic scoliosis is one of the most invasive surgical procedures performed in children and adolescents. Because of the extensive surgical incision and massive tissue trauma, posterior spinal fusion causes severe postoperative pain. Intravenous patient-controlled analgesia with opioids has been the mainstay of postoperative pain management in these patients. However, the use of systemic opioids is sometimes limited by opioid-related side effects, resulting in poor analgesia. To improve pain management while reducing opioid consumption and opioid-related complications, concurrent use of analgesics and analgesic modalities with different mechanisms of action seems to be rational. The efficacy of intrathecal opioids and nonsteroidal anti-inflammatory drugs as components of multimodal analgesia in scoliosis surgery has been well established. However, there is either controversy or insufficient evidence regarding the use of other analgesic methods, such as continuous ketamine infusion, perioperative oral gabapentin, acetaminophen, continuous wound infiltration of local anesthetics, a single dose of systemic dexamethasone, and lidocaine infusion in this patient population. Moreover, appropriate combinations of analgesics have not been established. The aim of this literature review is to provide detailed information of each analgesic technique so that clinicians can make appropriate choices regarding pain management in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion.

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Comparisons of direct costs, outcomes, and cost-utility of decompression surgery with fusion versus decompression alone for degenerative lumbar spondylolisthesis

Yagi M., Fujita N., Okada E., Tsuji O., Nagoshi N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 23 ( 4 ) 653 - 657 2018.07

ISSN 09492658

© 2018 Background: Cost-utility analysis of surgery for degenerative lumber spondylolisthesis (DS) is essential for healthcare providers and patients to select appropriate treatment. The purpose of this study was to review the cost-utility of decompression alone versus decompression with fusion for DS. Methods: A retrospective review of 99 consecutive patients who were treated for Meyerding grade 1 DS at two representative spine centers was performed. Patients with significant spinal instability were treated by decompression with fusion (F group, 40 patients); all others were treated by decompression surgery alone (D group, 59 patients). All patients were followed for three years. Demographic and radiographic data, health-related quality of life (HRQoL), and the direct cost for surgery were analyzed, and the incremental cost-effectiveness ratio (ICER) was determined using cost/quality-adjusted life years (QALY). Results: There were no differences between the groups in baseline demographics (D vs. F: age 68 ± 9 vs. 66 ± 7 years; 37% vs. 40% female) or HRQoL (ODI: D, 41 ± 16 vs. F, 46 ± 13%). The F group had a higher initial-surgery cost ($18,992 ± 2932) but lower reoperation frequency (7%) than the D group ($7660 ± 2182 and 12%, respectively). The three-year total direct cost was higher for F than for D ($19,222 ± 3332 vs. $9668 ± 6,168, p =.01). ICER was higher for F at one year ($136,408 ± 187,911 vs. $237,844 ± 212,049, p <.01), but was comparable for F and D at three years (D, $41,923 ± 44,503 vs. F, $51,313 ± 32,849, p =.17). Conclusion: At the three-year follow-up, the two methods had comparable cost-utility. Both methods were cost-effective (defined as an ICER within three times the per-capita gross domestic product).

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A screening method to distinguish syndromic from sporadic spinal extradural arachnoid cyst

Ogura Y., Yabuki S., Fujibayashi S., Okada E., Iwanami A., Watanabe K., Nakamura M., Matsumoto M., Ishii K., Ikegawa S.

Journal of Orthopaedic Science (Journal of Orthopaedic Science) 23 ( 3 ) 455 - 458 2018.05

ISSN 09492658

© 2018 The Japanese Orthopaedic Association Background: Spinal extradural arachnoid cyst (SEDAC) is a cystic lesion that protrudes into the epidural space from a small dural defect. Early diagnosis of SEDAC is important because its expansion causes neurological damage. Two types of SEDAC, syndromic and sporadic, are present. Syndromic SEDAC is inherited as a part of lymphedema-distichiasis syndrome caused by mutations in the FOXC2 gene; however, it is often mistaken as sporadic because of low penetrance. It is not reasonable to conduct a genetic testing for all SEDAC patients and their family members. The aim of this study is to establish an effective screening method to distinguish syndromic SEDAC from sporadic SEDAC. Methods: We performed a retrospective review of medical records and imaging studies of 29 subjects who were diagnosed with SEDAC. Clinical features, family history and magnetic resonance imaging (MRI) were analyzed. Mutations in FOXC2 were examined by Sanger-sequencing of the entire coding region of the genes. SEDAC having a mutation in FOXC2 gene was defined with syndromic SEDAC. Results: Eleven subjects had a heterozygous mutation in FOXC2. They were all familial and hence syndromic SEDAC. Only one proband had known family history of SEDAC at diagnosis. MRI findings and physical examinations, especially eye and leg examinations, were quite useful to screen syndromic SEDAC. Physical examination often showed accompanying lymphedema and distichiasis in syndromic SEDAC. Syndromic SEDAC tended to have multiple cysts out of the thoracolumbar area. Conclusions: We established an effective screening method based on physical examinations and MRI findings.

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Low Bone-Mineral Density Is a Significant Risk for Proximal Junctional Failure after Surgical Correction of Adult Spinal Deformity

Yagi M., Fujita N., Tsuji O., Nagoshi N., Asazuma T., Ishii K., Nakamura M., Matsumoto M., Watanabe K.

Spine (Spine) 43 ( 7 ) 485 - 491 2018.04

ISSN 03622436

Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design. A propensity-matched comparison of risk factors for proximal junctional failure (PJF), which is a symptomatic proximal junctional kyphosis developing after corrective surgery for adult spinal deformity (ASD). Objective. To elucidate the role of bone strength for developing PJF. Summary of Background Data. PJF, a devastating complication of corrective surgery for ASD, often recurs even after revision surgery. Most studies of risk factors for PJF are retrospective and have a selection bias in surgical strategy, making it difficult to identify modifiable PJF risk factors. Methods. We conducted propensity-matched comparisons of 113 surgically treated ASD patients who were followed for at least 2 years, to elucidate whether low bone-mineral density (BMD) was a true risk factor for PJF in a uniform population from a multicenter database. Patients were grouped as having mildly low to normal BMD (M group; T-score≧-1.5) or significantly low BMD (S group; T-score<-1.5), and were propensity-matched for age, upper and lower instrumented vertebrae, history of spine surgery, and Schwab-Scoliosis Research Society (SRS) ASD classification. PJF was defined as a ≥20° increase from the baseline proximal junction angle with a concomitant deterioration of at least one SRS-Schwab sagittal modifier grade, or any type of proximal junctional kyphosis requiring revision. Results. PJF developed in 22 of 113 patients (19%). There were 48 propensity-matched patients in the M and S groups (24 in each) with similar parameters for age, body mass index, number of vertebrae involved, C7SVA, pelvic incidence -LL, and SRS-Schwab type. In this propensity-matched population, the incidence of PJF was significantly higher in the S group (33% vs. 8%, P<0.01, odds ratio 6.4, 95% CI: 1.2-32.3). Conclusion. Low BMD was a significant risk factor for PJF in this propensity-matched cohort (odds ratio 6.4). Surgeons should consider prophylactic treatments when correcting ASD in patients with low BMD. Level of Evidence: 3

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A cost-effectiveness comparisons of adult spinal deformity surgery in the United States and Japan

Yagi M., Ames C., Keefe M., Hosogane N., Smith J., Shaffrey C., Schwab F., Lafage V., Shay Bess R., Matsumoto M., Watanabe K.

European Spine Journal (European Spine Journal) 27 ( 3 ) 678 - 684 2018.03

ISSN 09406719

© 2017, Springer-Verlag GmbH Germany. Purpose: Information about the cost-effectiveness of surgical procedures for adult spinal deformity (ASD) is critical for providing appropriate treatments for these patients. The purposes of this study were to compare the direct cost and cost-effectiveness of surgery for ASD in the United States (US) and Japan (JP). Methods: Retrospective analysis of 76 US and 76 JP patients receiving surgery for ASD with ≥2-year follow-up was identified. Data analysis included preoperative and postoperative demographic, radiographic, health-related quality of life (HRQOL), and direct cost for surgery. An incremental cost-effectiveness ratio (ICER) was determined using cost/quality-adjusted life years (QALY). The cost/QALY was calculated from the 2-year cost and HRQOL data. Results: JP exhibited worse baseline spinopelvic alignment than the US (pelvic incidence and lumbar lordosis: 35.4° vs 22.7°, p OpenSPiltSPi 0.01). The US had more three-column osteotomies (50 vs 16%), and shorter hospital stay (7.9 vs 22.7 days) (p OpenSPiltSPi 0.05). The US demonstrated worse postoperative ODI (41.3 vs. 33.9%) and greater revision surgery rate (40 vs 10%) (p OpenSPiltSPi 0.05). Due to the high initial cost and revision frequency, the US had greater total cost ($92,133 vs. $49,647) and cost/QALY ($511,840 vs. $225,668) at 2-year follow-up (p OpenSPiltSPi 0.05). Conclusion: Retrospective analysis comparing the direct costs and cost-effectiveness of ASD surgery in the US vs JP demonstrated that the total direct costs and cost/QALY were substantially higher in the US than JP. Variations in patient cohort, healthcare costs, revision frequencies, and HRQOL improvement influenced the cost/QALY differential between these countries.

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Acute regrowth and dissemination of a mature spinal cord teratoma after partial resection

Kawai M., Nagoshi N., Iwanami A., Mikami S., Tsuji O., Fujita N., Yagi M., Watanabe K., Ishii K., Nakamura M., Matsumoto M.

BMJ Case Reports (BMJ Case Reports) 2018 2018

© BMJ Publishing Group Limited 2018. A 23-year-old man presented with difficulty walking and leg pain and numbness. MRI revealed a cystic mass at Th11-12 and a pineal-region tumour. The patient underwent surgery to resect the thoracic-level mass. The tumour adhered strongly to the neural tissue and could only be partially resected. On pathological examination, the resected tumour was diagnosed as a mature teratoma. The tumour regrew and disseminated within 3 months after resection. Both the spinal cord tumour and the tumour in the pineal region shrank significantly after chemotherapy and radiotherapy. Although the tumour was pathologically diagnosed as a mature teratoma, we suspect that the residual tumour contained an immature or malignant component. Thus, careful follow-up observation is mandatory after partial resection of a mature teratoma. In addition, because teratomas can disseminate in the central nervous system, the presence of teratoma should prompt an examination of both the spinal cord and brain.

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Total resection of cervical ventral intramedullary cavernous hemangiomas with an anterior corpectomy

Nagoshi N., Ishii K., Kameyama K., Tsuji O., Okada E., Fujita N., Yagi M., Matsumoto M., Nakamura M., Watanabe K.

Spine Surgery and Related Research (Spine Surgery and Related Research) 2 ( 4 ) 331 - 334 2018

Introduction: Intramedullary lesions and tumors are generally accessed by a posterior approach. However, if the lesion is located on the ventral side of the spinal cord, a posterior resection with myelotomy poses technical difficulties. We report two cases of complete resection of a cervical ventral intramedullary cavernous hemangioma using an anterior approach. Case Report: Two cases of intramedullary cavernous hemangioma located on the ventral side of the spinal cord were successfully treated by total resection with anterior cervical corpectomy followed by anterior spinal fusion with an autologous bone strut from the iliac crest. In both cases, the postoperative course was uneventful, and there was no neurological deficit. Bony fusion was achieved, and there was no recurrence or complication during a follow-up period of at least two years. Conclusions: Here, we describe an anterior approach for total resection of cavernous hemangiomas on the ventral side of the cervical spinal cord. Outcomes were stable two years after the operations. Although the method should be assessed with more patients and a longer follow-up time, this anterior approach may be useful for the radical resection of a vascular malformation or tumor.

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A 20-year prospective longitudinal study of degeneration of the cervical spine in a volunteer cohort assessed using MRI follow-up of a cross-sectional study

Daimon K., Fujiwara H., Nishiwaki Y., Okada E., Nojiri K., Watanabe M., Katoh H., Shimizu K., Ishihama H., Fujita N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

Journal of Bone and Joint Surgery - American Volume (Journal of Bone and Joint Surgery - American Volume) 100 ( 10 ) 843 - 849 2018

ISSN 00219355

Background: Few studies have addressed in detail long-term degenerative changes in the cervical spine. In this study, we evaluated the progression of degenerative changes of the cervical spine that occurred over a 20-year period in an originally healthy cohort. We also sought to clarify the relationship between the progression of cervical degenerative changes and the development of clinical symptoms. Methods: For this prospective follow-up investigation, we recruited 193 subjects from an original cohort of 497 participants who had undergone magnetic resonance imaging (MRI) of the cervical spine between 1993 and 1996. The subjects were asked about the presence or absence of cervical spine-related symptoms. Degenerative changes of the cervical spine were assessed on MRI using an original numerical grading system. The relationship between the progression of degenerative changes and the onset of clinical symptoms was evaluated by logistic regression analysis. Results: Degeneration in the cervical spine was found to have progressed in 95% of the subjects during the 20-year period. The finding of a decrease in signal intensity of the intervertebral disc progressed in a relatively high proportion of the subjects in all age groups and occurred with similar frequency (around 60%) at all intervertebral disc levels. The rate of progression of other structural failures on MRI increased with age and was highest at C5-C6. The progression of foraminal stenosis was associated with the onset of upper-limb pain (odds ratio, 4.71 [95% confidence interval, 1.02 to 21.7]). Conclusions: A progression of degenerative changes in the cervical spine on MRI over the 20-year period was detected in nearly all subjects. There was no relationship between the progression of degeneration on MRI and the development of clinical symptoms, with the exception of an association found between foraminal stenosis and upper-limb pain. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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Spinal arteriovenous fistula coexisting within a spinal lipoma: report of two cases

Horiuchi Y, Iwanami A, Akiyama T, Hikata T, Watanabe K, Yagi M, Fujita N, Okada E, Nagoshi N, Tsuji O, Ishii K, Yoshida K, Nakamura M, Matsumoto M

Spinal cord series and cases 3 17079 2017

Research paper (scientific journal)

Physical Activities and Lifestyle Factors Related to Adolescent Idiopathic Scoliosis.

Watanabe K, Michikawa T, Yonezawa I, Takaso M, Minami S, Soshi S, Tsuji T, Okada E, Abe K, Takahashi M, Asakura K, Nishiwaki Y, Matsumoto M

The Journal of bone and joint surgery 99 ( 4 ) 284 - 294 2017

Research paper (scientific journal)

Increased sorbitol levels in the hypertrophic ligamentumflavum of diabetic patients with lumbar spinal canal stenosis

Luo J, Huang L, Chen Z, Zeng Z, Miyamoto T, Wu H, Zhang Z, Pan Z, Fujita N, Hikata T, Iwanami A, Tsuji T, Ishii K, Nakamura M, Matsumoto M, Watanabe K, Cao K

Journal of orthopaedic research 35 ( 5 ) 1058 - 1066 2017

Research paper (scientific journal)

Compound Heterozygosity for Null Mutations and a Common Hypomorphic Risk Haplotype in TBX6 Causes Congenital Scoliosis

Takeda K, Kou I, Kawakami N, Iida A, Nakajima M, Ogura Y, Imagawa E, Miyake N, Matsumoto N, Yasuhiko Y, Sudo H, Kotani T, Japan Early Onset Scoliosis Research Group, Nakamura M, Matsumoto M, Watanabe K, Ikegawa S

Human mutation 38 ( 3 ) 317 - 323 2017

Research paper (scientific journal)

Scoliosis is a Risk Factor for Gastroesophageal Reflux Disease in Adult Spinal Deformity

Hosogane N, Watanabe K, Yagi M, Kaneko S, Toyama Y, Matsumoto M

Clinical spine surgery 30 ( 4 ) E480 - E484 2017

Research paper (scientific journal)

Onset and remodeling of coronal imbalance after selective posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis (a pilot study)

Ishikawa M, Cao K, Pang L, Fujita N, Yagi M, Hosogane N, Tsuji T, Machida M, Ishihara S, Nishiyama M, Fukui Y, Nakamura M, Matsumoto M, Watanabe K

Scoliosis and Spinal Disorders 12 16 2017

Research paper (scientific journal)

Histomorphometric analysis of minimodeling in the vertebrae in postmenopausal patients treated with anti-osteoporotic agents

Hikata T, Hasegawa T, Horiuchi K, Fujita N, Iwanami A, Watanabe K, Ishii K, Nakamura M, Amizuka N, Matsumoto M

Bone reports 5 286 - 291 2017

Research paper (scientific journal)

Effect of the upper instrumented vertebral level (upper vs. lower thoracic spine) on gait ability after corrective surgery for adult spinal deformity

Yagi M, Fujita N, Tsuji O, Nagoshi N, Yato Y, Asazuma T, Ishii K, Nakamura M, Matsumoto M, Watanabe K

The Spine Journal (Spine Journal) 18 ( 1 ) 130 - 138 2017

Research paper (scientific journal), ISSN 15299430

© 2017 Elsevier Inc. Background Context The relationship between gait pattern and the level of upper instrumented vertebra (UIV) in surgically treated patients with adult spinal deformity (ASD) has not been fully documented. Purpose This study aimed to assess the effect of UIV level for the gait pattern in ASD. Study Design/Setting A prospective case series was carried out. Patient Sample Thirty surgically treated consecutive female ASD with lumbosacral fusion (age 67.0±8.4 years; body mass index 22.7±2.4 kg/m 2 ; Cobb angle 49.9°±21.3°; coronal vertical axis 1.5±3.6 cm; C7 sagittal vertical axis [C7SVA] 9.3±5.3 cm; pelvic incidence-lumbar lordosis 35.4°±25.8°; and lean volume of the lower leg 5.5±0.9 kg) were categorized into upper thoracic [UT] group or lower thoracic [LT] group based on the level of UIV (UT; UIV T2–T5, LT; UIV T9–T11), and the gait pattern were compared before and after corrective spine surgery. Outcome Measures Scoliosis Research Society Patient Questionnaire, Oswestry Disability Index, and force plate analysis were the outcome measures. Methods All subjects underwent gait analysis on a custom-built force plate. Dual-energy X-ray absorptiometry. Subjects were followed-up for at least 2 years postoperation. Results The UT group had larger baseline Cobb angle, whereas the LT group had larger C7SVA (UT vs. LT; Cobb angle: 59.2±22.9 vs. 44.6±17.4° p=.03, C7SVA: 10.9±8.7 vs. 12.0±7.1 cm, p=.03). Preoperatively, no difference was found in gait velocity and stride between UT and LT group, whereas the right and left difference of step length was significantly large in UT group (velocity: 55.0±12.5 vs. 53.6±9.0 m/min, stride: 99.7±13.0 vs. 97.8±13.6 cm, step length; 10.4±4.9 vs. 5.6%±3.3%). Coronal and sagittal alignments were significantly improved in both groups (total; Cobb angle: 19.4°±10.6° C7SVA: 5.3±2.9 cm, PI–LL: 12.1°±5.1°). Gait pattern, stride, and velocity all improved significantly after surgery (total; velocity: 62.3±8.9m/min, stride: 106.8±12.3 cm, p=.01). The knee angle at the heel contact phase and hip range of motion (ROM) were also significantly improved at postoperation (total; hip ROM: preoperation: 29.2°±9.1° postoperation: 36.2°±4.8° knee angle; preoperation: 10.6°±6.6° postoperation: 4.4°±2.8°). No difference was observed for the pelvis and shoulder rotation on the horizontal plane at postoperation in both groups (total; pelvis rotation; preoperation: 7.4°±3.4° postoperation: 7.9°±2.4° shoulder rotation; preoperation: 7.4°±2.9° postoperation: 8.7°±3.6°). The head vertical deviation was also not changed postoperatively in both groups (preoperation: 3.1±0.9 cm, postoperation: 3.1±0.8 cm). Conclusions Both UT and LT groups achieved similar improvement of gait ability and pattern after surgery. Additional studies will be needed to further define the effect of UIV for the activity of daily living such as fast walking, stepping the stairs, or standing from the chair in ASDs.

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Response to Lefebvre et al

Takeda K, Kou I, kawakami N, Yasuhiko Y, Ogura Y, Imagawa E, Miyake N, Matsumoto N, Sudo H, Kotani T, Japan Early Onset Scoliosis Research Group, Nakamura M, Matsumoto M, Watanabe K, Ikegawa S

Clinical Genetics 2017

Research paper (scientific journal)

Factors associated with postoperative C5 palsy after expansive open-door laminoplasty: retrospective cohort study using multivariable analysis

Tsuji T, Matsumoto M, Nakamura M, Ishii K, Fujita N, Chiba K, Watanabe K

European Spine Journal 26 2410 - 2416 2017

Research paper (scientific journal)

Presence of Modic type 1 change increases risk of postoperative pyogenic discitis following decompression surgery for lumbar canal stenosis

Ninomiya K, Fujita N, Hosogane N, Hikata T, Watanabe K, Tsuji O, Nagoshi N, Yagi M, Kaneko S, Fukui Y, Koyanagi T, Shiraishi T, Tsuji T, Nakamura M, Matsumoto M, Ishii K

Journal of Orthopaedic Science 2017

Research paper (scientific journal)

Correlation between preoperative physical signs and functional outcomes after laminoplasty for ossification of the posterior longitudinal ligament

Tsuji T, Fujita N, Watanabe K, Nakamura M, Matsumoto M, Ishii K

Journal of orthopaedic science 22 ( 2 ) 266 - 269 2017

Research paper (scientific journal)

Low Bone-Mineral Density Is a Significan Risk for Proximal Junctional failure After Surgical correction of Adult Spinal Deformity

Yagi M, Fujita N, Tsuji O, Nagoshi N, Asazuma T, Ishii K, Nakamura M, Matsumoto M, Watanabe K

Spine 42 2017

Research paper (scientific journal)

Idiopathic Spinal epidural fat accumulation is associated with hyperlipidemia

Ishihara S, Fujita N, Yagi M, Tsuji T, Michikawa T, Nishiwaki Y, Fukui Y, Horiuchi K, Ishii K, Nakamura M, Matsumoto M, Watanabe K

Spine (Spine) 43 ( 8 ) E468 - E473 2017

Research paper (scientific journal), ISSN 03622436

© 2018 Wolters Kluwer Health, Inc. Study Design. Single-center retrospective analysis of consecutively collected data. Objective. To determine the clinical characteristics of idiopathic spinal epidural lipomatosis (SEL). Summary of Background Data. SEL is associated with the overt accumulation of nonencapsulated adipose tissue in the epidural space, leading to spinal cord or nerve root compression. The etiology of this condition is currently not completely understood. Methods. Data of 166 male patients who underwent primary surgery for lumbar spinal canal stenosis (LSS) from May 2013 to February 2016 were retrospectively reviewed. Participants were divided into three groups based on the degree of epidural lipomatous lesion. Patient data of age at surgery, body mass index, prevalence of common noncommunicable diseases, blood tests, arteriosclerotic index, and preoperative clinical scores (assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire) were evaluated. Multivariate analysis was performed to assess the potential associated factors for idiopathic SEL. Results. Patients with LSS with severe SEL had a significantly higher body mass index and elevated serum levels of total cholesterol and triglyceride compared with those without SEL. Analysis of preoperative clinical scores revealed that patients with SEL experienced pain more frequently and showed less walking ability than did those without SEL. Multivariate analysis revealed that hyperlipidemia was significantly associated with idiopathic SEL (odds ratio =3.74, 95% confidence interval =1.31-10.64). Conclusion. Our data suggest that aberrant lipid metabolism is related to the pathogenesis of idiopathic SEL and that patients with LSS with idiopathic SEL have more severe pain than do those without SEL.

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A cost -effectiveness comparisons of adult spinal deformity surgry in the United States and Japan

Yagi M, Ames CP, Keefe M, Hosogane N, Smith JS, Shaffrey CI, Schwab F, Lafage V, Bess RS, Matsumoto M, Watanabe K, International Spine Study Group

European Spine Journal 2017

Research paper (scientific journal)

Risk factor analysis of kyphotic malalignment after cervical intramedullary tumor resection in adults

Nori S, Iwanami A, Yasuda A, Nagoshi N, Fujita N, Hikata T, Yagi M, Tsuji T, Watanabe K, Momoshima S, Matsumoto M, Nakamura M, Ishii K

Journal of neurosurgery 1 - 10 2017

Research paper (scientific journal)

A Replication Study for the Association of rs11190870 With Curve Severity in Adolescent Idiopathic Scoliosis in Japanese

Takahashi Y, Kou I, Ogura Y, Miyake A, Takeda K, Nakajima M, Minami S, Kawakami N, Uno K, Ito M, Yonezawa I, Kaito T, Yanagida H, Watanabe K, Taneichi H, Harimaya K, Taniguchi Y, Kotani T, Tsuji T, Suzuki T, Sudo H, Fujita N, Yagi M, Chiba K, Kono K, Sakuma T, Akazawa T, Nishida K, Kakutani K, Shigematsu H, Iida T, Demura S, Hosogane N, Okada E, Nakamura M, Matsumoto M, Watanabe K, Ikegawa S

Spine (Spine) 43 ( 10 ) 688 - 692 2017

Research paper (scientific journal), ISSN 03622436

© 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design. Case-only study. Objective. The aim of this study was to confirm the association of rs11190870 with adolescent idiopathic scoliosis (AIS) severity in Japanese patients with AIS. Summary of Background Data. Although the association of rs11190870 with AIS susceptibility is replicated in multiple ethnics, the association of rs11190870 with curve severity is controversial. Since the previous studies are of small, we performed a replication study using far larger number of patients than previous studies. Methods. A total of 1860 Japanese patients with AIS who had reached skeletal maturity or undergone surgical fusion were included in the study. We evaluated the association between rs11190870 and AIS progression for the entire group, and then for patients grouped according to a severe curve (a Cobb angle of ≥40°) or mild curve (a Cobb angle <30°). Because braces could affect the results of the present study, patients in the mild-curve group were divided according to whether or not they had worn a brace. We then evaluated associations between rs11190870 genotype and curve severity in these groups. Results. The mean Cobb angles were 54.8° ± 12.1° in the severe-curve group and 24.4° ± 4.0° in the mild-curve group. The difference in rs11190870 risk-allele frequency between the severe- and mild-curve groups was evaluated. No significant differences were observed. We then examined the association of rs11190870 risk-allele frequency between patients in the mild- and severe-curve groups using the χ 2 test for three models, and found a marginal association between rs11190870 and curve severity in the dominant model (P = 0.035, odds ratio = 1.51). Conclusion. We found no association between rs11190870 and curve severity using the criteria of previous study. However, we found a marginal association between rs11190870 and curve severity. Large-scale replication studies that consider skeletal maturity and brace history, including replication studies in other ethnic groups, would be helpful for clarifying the association. Level of Evidence: 4.

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Fine-tuning the Predictive Model for Proximal Junctional Failure in Surgically Treated Patients With Adult Spinal Deformity

Yagi M, Fujita N, Okada E, Tsuji O, Nagoshi N, Asazuma T, Ishii K, Nakamura M, Matsumoto M, Watanabe K

Spine (Spine) 43 ( 11 ) 767 - 773 2017

Research paper (scientific journal), ISSN 03622436

Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design. Multicenter retrospective study. Objective. To validate and improve the predictive model for proximal junctional failure (PJF) with or without the bone mineral density (BMD) score. Summary of Background Data. PJF is a serious complication of surgery for adult spinal deformity (ASD). A predictive model for PJF was recently reported that has good accuracy, but does not include BMD, a known PJF risk factor, as a variable. Methods. We included 145 surgically treated ASD patients who were older than 50 at the time of surgery and had been followed up for at least 2 years. Variables included age, sex, body mass index (BMI), fusion level, upper and lower instrumented vertebral (UIV and LIV) level, primary or revision surgery, pedicle subtraction osteotomy (PSO), Schwab-SRS type, and BMD. PJF was defined as a ≥ 20° increase from baseline (immediately postoperative) of the proximal junctional angle with concomitant deterioration of at least 1 SRS-Schwab sagittal modifier grade, or any proximal junctional kyphosis requiring revision. Decision-making trees were constructed using the C5.0 algorithm with 10 different bootstrapped models, and validated by a 7:3 data split for training and testing; 112 patients were categorized as training and 33 as testing samples. Results. PJF incidence was 20% in the training samples. Univariate analyses showed that BMD, BMI, pelvic tilt (PT), UIV level, and LIV level were PJF risk factors. Our predictive model was 100% accurate in the testing samples with an AUC of 1.0, indicating excellent fit. The best predictors were (strongest to weakest): PT, BMD, LIV level (pelvis), UIV level (lower thoracic), PSO, global alignment, BMI, pelvic incidence minus lumbar lordosis, and age. Conclusion. A successful model was developed for predicting PJF that included BMD. Our model could inform physicians about patients with a high risk of developing PJF in the perioperative period. Level of Evidence: 4.

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小児の特発性脊柱側彎症手術におけるデキサメタゾンの術後悪心・嘔吐予防効果

関博志, 若宮里恵, 伊原奈帆, 出野智史, 蓑島梨恵, 村瀬玲子, 高木美沙, 渡辺航太, 佐藤真人, 森崎浩

麻酔 66 ( 3 ) 298 - 302 2017

Research paper (scientific journal)

腰椎変性疾患に対する２椎間の後方経路腰椎椎体間固定術後の椎体間ケージ沈み込みの危険因子

磯貝宜広, 渡邉航太, 日方智宏, 藤田順之, 八木　満, 辻収彦, 名越慈人, 中村雅也, 松本守雄, 石井　賢

臨床整形外科 52 ( 7 ) 685 - 690 2017

Research paper (scientific journal)

【高齢者の脊柱変形UP TO DATE】(第2章)治療 PROXIMAL JUNCTIONAL KYPHOSISの治療

八木満, 藤田順之, 松本守雄, 渡辺航太

脊椎脊髄ジャーナル 30 ( 4 ) 477 - 482 2017

Research paper (scientific journal)

【高齢者の脊柱変形UP TO DATE】(第2章)治療脊柱変形の矯正手術の実際後方から

渡辺航太, 藤田順之, 八木満, 松本守雄

脊椎脊髄ジャーナル 30 ( 4 ) 351 - 356 2017

Research paper (scientific journal)

【椎間板変性の病態と治療】椎間板の微小環境低酸素、酸化ストレスの観点から

藤田順之, 鈴木悟士, 渡辺航太, 石井賢, 松本守雄, 中村雅也

整形・災害外科 60 ( 3 ) 273 - 277 2017

Research paper (scientific journal)

【LATERAL INTERBODY FUSION(LIF)-我が国における現況と展望-】 EXTREME LATERAL INTERBODY FUSION(XLIF) 適応と手術手技

石井賢, 塩野雄太, 磯貝宜広, 船尾陽生, 細金直文, 八木満, 日方智宏, 渡辺航太, 松本守雄

整形外科最小侵襲手術ジャーナル ( 82 ) 2 - 12 2017

Research paper (scientific journal)

【脊椎・脊髄疾患と筋萎縮】脊柱矢状面バランスと筋萎縮

八木満, 藤田順之, 石井賢, 中村雅也, 松本守雄, 渡辺航太

脊椎脊髄ジャーナル 30 ( 5 ) 579 - 584 2017

Research paper (scientific journal)

二期的手術により全摘できた頸胸髄上衣腫の1例

鈴木悟士, 岩波明生, 安田明正, 藤田順之, 日方智宏, 渡辺航太, 中村雅也, 松本守雄, 石井賢

臨床整形外科 52 ( 3 ) 303 - 309 2017

Research paper (scientific journal)

腰椎変性疾患に対する２椎間の後方経路腰椎椎体間固定術後の椎体間ケージ沈み込みの危険因子

磯貝宜広, 渡邉航太, 日方智宏, 藤田順之, 八木　満, 辻収彦, 名越慈人, 中村雅也, 松本守雄, 石井　賢

臨床整形外科 52 ( 7 ) 685 - 690 2017

Research paper (scientific journal)

Myelopathy due to Spinal Extramedullary Hematopoiesis in a Patient with Polycythemia Vera

Ito S, Fujita N, Hosogane N, Nagoshi N, Yagi M, Iwanami A, Watanabe K, Tsuji T, Nakamura M, Matsumoto M, Ishii K

Journal of sports medicine 2416365 2017

Research paper (scientific journal)

Compound heterozygosity for null mutations and a common hypomorphic risk haplotype in TBX6 causes congenital scoliosis

Human mutation 38 ( 3 ) 317 - 323 2017

Asymmetrical pedicle subtraction osteotomy for progressive kyphoscoliosis caused by a pediatric Chance fracture: acase report

Suzuki S, Fujita N, Hikata T, Iwanami A, Ishii K, Nakamura M, Matsumoto M, Watanabe K

Scoliosis and Spinal Disorders 12 8 2017

Research paper (scientific journal)

Response to Lefebvre et al

Takeda K, Kou I, Kawakami N, Yasuhiko Y, Ogura Y, Imagawa E, Miyake N, Matsumoto N, Sudo H, Kotani T, Japan Early Onset Scoliosis Research Group, Nakamura M, Matsumoto M, Watanabe K, Ikegawa S

Clinical genetics 92 ( 5 ) 563 - 564 2017

Research paper (scientific journal)

A functional variant in MIR4300HG, the host gene of microRNA MIR4300 is associated with progression of adolescent idiopathic scoliosis

Ogura Y, Kou I, Takahashi Y, Takeda K, Minami S, Kawakami N, Uno K, Ito M, Yonezawa I, Kaito T, Yanagida H, Watanabe K, Taneichi H, Harimaya K, Taniguchi Y, Kotani T, Tsuji T, Suzuki T, Sudo H, Fujita N, Yagi M, Chiba K, Kubo M, Kamatani Y, Nakamura M, Matsumoto M, Japan Scoliosis Clinical Research Group, Watanabe K, Ikegawa S, Japan Scoliosis Clinical Research Group

Human molecular genetics 26 ( 20 ) 4086 - 4092 2017

Research paper (scientific journal)

Exploration for reliable radiographic assessment method for hinge-like hypermobility at atlanto-occipital joint

Kaneko S, Ishii K, Watanabe K, Tsuji T, Nakamura M, Matsumoto M, Yato Y, Asazuma T

European spine journal (European Spine Journal) 27 ( 6 ) 1303 - 1308 2017

Research paper (scientific journal), ISSN 09406719

© 2017, The Author(s). Purpose: Hinge-like hyper-mobility is occasionally observed at the atlanto-occipital (O-C1) joint. However, it has not been clear if this kind of hinge-like hyper-mobility at the O-C1 joint should be regarded as “pathologic”, or referred to as “instability”. To solve this issue, we aimed to establish a reliable radiographic assessment method for this specific type of O-C1 instability and figure out the “standard value” for the range of motion (ROM) of the O-C1 joint. Methods: To figure out the standard range of the O-C1 angle, we acquired magnetic resonance imaging (MRI) sagittal views of the cervical spine for 157 healthy volunteers [average: 37.4 year-old (yo)] without spine diseases, at neutral, maximum flexion and maximum extension positions. Results: The average value (AVE) for ROM of O-C1 angle was 9.91°. The standard value for ROM of O-C1 angle was calculated as 0°–21°. There was no statistically significant gender difference. We also found that the older population (≧ 40 yo) significantly had a larger ROM of O-C1 angle (AVE: 11.72°) compared to the younger population (< 40 yo) (AVE: 8.99°). Conclusions: We consider that hinge-like instability at O-C1 joint, which cannot be assessed by measuring Powers ratio, can be assessed by measuring the range of O-C1 angles using dynamic-MRI. Evaluation of O-C1 instability is important especially when we perform surgical treatment for diseases with upper cervical instability (such as retro-odontoid pseudotumor). We consider that the current study provides important information in such a case.

Access to Document (DOI)

The Unfolded Protein Response Mediated by PERK is casually related to the Pathogenesis of Intervertebral Disc Degeneration

Fujii T, Fujita N, Suzuki S, Tsuji T, Takaki T, Umezawa K, Watanabe K, Miyamoto T, Horiuchi K, Matsumoto M, Nakamura M

Journal of orthopaedic research (Journal of Orthopaedic Research) 36 ( 5 ) 1334 - 1345 2017

Research paper (scientific journal), ISSN 07360266

© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. Although the number of patients with intervertebral disc (IVD) degeneration is increasing in aging societies, its etiology and pathogenesis remain elusive and there is currently no effective treatment to prevent this undesirable condition. The unfolded protein response (UPR) is a cellular machinery that plays critical roles in handling endoplasmic reticulum (ER) stress, a condition caused by the accumulation of unfolded proteins in the ER lumen. This study aimed to elucidate the potential role of the UPR mediated by pancreatic endoplasmic reticulum kinase (PERK), one of the major ER stress sensors in mammalian cells, in the development of IVD degeneration. IVD degeneration was artificially induced in Wister rats by percutaneously puncturing the coccyx IVDs and human IVDs were collected from patients who underwent spinal surgery. Expression of the UPR target genes was elevated in degenerative IVDs in both humans and rats. The induction of ER stress in annulus fibrosus cells significantly increased the transcripts for tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in a nuclear factor (NF)-κB pathway-dependent manner. The expression of TNF-α and IL-6 was significantly reduced by treatment with a selective PERK inhibitor, GSK2606414, and by gene silencing against PERK and activating transcription factor 4 (ATF4) transcripts. Our findings indicate that the UPR mediated by the PERK pathway is causally related to the development of IVD degeneration, suggesting that PERK may be a potential molecular target for suppressing the degenerative changes in IVDs. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1334–1345, 2018.

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Epithelioid Hemangioma of the Thoracic Spine : A case Report and Review of the Literature.

Okada E, Matsumoto M, Nishida M, Iga T, Morishita M, Tazuka M, Mukai K, Kobayashi E, Watanabe k

The journal of Spine Cord Medicine (Journal of Spinal Cord Medicine) 42 ( 6 ) 1 - 6 2017

Research paper (scientific journal), ISSN 10790268

Context: Osseous epithelioid hemangioma is uncommon, and reports of epithelioid hemangiomas of the spine are especially rare. Study Design: Case report. Findings: A 43-year-old male was referred to our department with progressive gait disturbance. CT scans showed a lucent mass in the vertebral body at the T3 level. MRI of the thoracic spine showed a strongly enhanced mass compressing the spinal cord. The patient underwent laminectomy from T2 to T4, debulking of the tumor, and posterior fusion from T1 to T5. After the operation, the patient's neurological status improved significantly, and he was able walk without assistance. Histological examination determined that the tumor was an epithelioid hemangioma. The patient was treated with 40 Gy radiation for local control of the tumor. The patient could walk without difficulty 12 months after the surgery. Conclusion: This is a rare example of an epithelioid hemangioma that developed in the thoracic spine and compressed the spinal cord, and was treated successfully.

Access to Document (DOI)

Surgical Correction of Severe Kyphoscoliosis Associated with Crouzon Syndrome with Serious Postoperative Respiratory Problems

Umezu T, Fujita N, Yagi M, Tsuji O, Nagoshi N, Ishii K, Nakamura M, Matsumoto M, Watanabe K

JBJS case connector 7 ( 4 ) e98 2017

Research paper (scientific journal)

脊髄離断術後に脊髄摘出を２回施行した胸髄発生Glioblastomaの1例．

櫻井孝紀, 岩波明生, 藤田順之, 日方智宏, 渡辺航太, 石井　賢, 松本守雄, 中村雅也

日本脊髄障害医学会雑誌　 29 ( 1 ) 132-134 2016.05

Research paper (scientific journal)

Genome-wide association study for adolescent idiopathic scoliosis.

Ogura Y, Kou I, Scoliosis J, Matsumoto M, Watanabe K, Ikegawa S

Clincal Calcium 26 ( 4 ) 553-00 2016.04

Research paper (scientific journal)

A chordoma-derived cell line U-CH1-N recapitulates the biological of notochordal nucleus pulposus cells

Fujita N, Suzuki S, Watanabe K, Ishii K, Watanabe R, Shimoda M, Takubo K, Tsuji T, Toyama Y, Miyamoto T, Horiuchi K, Nakamura M, Matsumoto M

Journal of Orthopaedic Research 34 ( 8 ) 1341-50 2016

Research paper (scientific journal)

Risk Factors of radiological adjacent disc degeneration with lumbar interbody fusion for degenerative spondylolisthesis.

Tsuji T, Watanabe K, Hosogane N, Fujita N, Ishi K, Chiba K, Toyama Y, Nakamura M, Matsumoto M

Journal of Orthopaedic Science 21 ( 2 ) 133 - 137 2016

Research paper (scientific journal)

Automatic Screening System for Scoliosis Utilizing Moire Pattern.

Choi R, Watanabe K, Nakamura M, Matsumoto M, Fujita N, Ogura Y, Tuji T, Wata K, Kotani T, Miyazaki M, Shigematsu H, Demura S, Takahashi M, Abe K, Yoshimtsu A.

FCV2016, Gifu 2016

Research paper (scientific journal)

Epidemiological survey of ossification of the posterior longitudinal ligament by using clinical investigation registration forms .

Tuji T, Chiba K, Hosogane N, Fujita N, Hikata T, Iwanami A, Watanabe K, Ishii K, Toyama Y, Nakamura M, Matsumoto M.

Journal of Orthopaedic Science 21 291-4 2016

Research paper (scientific journal)

Remodeling of the Cervical Facet Joint After Minimally Invasive Microendoscopic resection for Cervical Osteoid Osteoma

Hikata T, Fujita N, Iwanami A, Watanabe K, Nakamura M, Matsumoto M, Ishii K.

Spine 41 ( 19 ) E1191-E1194 2016

Research paper (scientific journal)

Generation of heterozygous fibrillin – 1 mutant cloned pigs from genome – edited foetal fibroblasts.

Umeyama K, Watanabe K, Watanabe M, Horiuchi K, Nakano K, Kitashiro M, Matsunari H, Kimura T, Arima Y, Sampetrean O, Nagaya M, Saito M, Saya H, Kosaki K, Nagashima H, Matsumoto M

Scientific Reports 6 24413 2016

Research paper (scientific journal)

Reliability Analysis of Spino-Pelvic Parameters in Adult Spinal Deformity:A Conparison of Whole Spine and Pelvic Rediographs.

Chen RQ, Hosogane N, Watanabe K, Funao H, Okada E, Fujita N, Hikata T, Iwanami a, Tsuji T, Ishii K, Abe T, Toyama Y, Nakamuara M, Matsumoto M

Spine 41 ( 4 ) 320-7 2016

Research paper (scientific journal)

The paravertebral muscle and psoas for the maintenance of global spinal alignment in patient with degenerative lumbar scokiksis.

Yagi M, Hosogane N, Watanabe K, Asazuma T, Matsumoto M, Keio Spine Research Group.

Spine Journal 16 ( 4 ) 451-8 2016

Research paper (scientific journal)

Potential involvement of obesity-associated chronic inflammation in the pathogenesis of idiopathic spinal epidural lipomatosis.

Fujita N, Hosogane N, Hikata T, Iwanami A, Watanabe K, Shiono Y, Okada E, Ishikawa M, Tsuji T, Shimoda M, Horiuchi K, Nakamura M, Matsumoto M, Ishii K.

Spine 41 ( 23 ) E1402-E1407 2016

Research paper (scientific journal)

chordoma-derived cell line U-CH1-N recapitulates the biological of notochordal nucleus pulposus cells.

Fujita N, Suzuki S, Watanabe K, Ishii K, Watanabe R, Shimoda M, Takubo K, Tsuji T, Toyama Y, Miyamoto T, Horiuchi K, Nakamura M, Matsumoto M

Journal of Orthopaedic Research 2016

Research paper (scientific journal)

Risk factors of radiological adjacent disc degeneration with lumbar interbody fusion for degenerative spondylolisthesis.

Tsuji T, Watanabe K, Hosogane N, Fujita N, Ishii K, Chiba K, Toyama Y, Nakamura M, Matsumoto M.

Journal of Orthopaedic Science 21 133-7 2016

Research paper (scientific journal)

Increased sorbitol levels in the hypertrophic ligamentumflavum of diabetuc patients with lumbar spinal canal stenosis.

Luo J, Huang L, Chen Z, ZengZ, Miyamoto T, Wu H, Zhang Z, Pan Z, Fujita N, Hikata T, Iwanami A, Tsuji T, Ishii K, Nakamura M, Matsumoto M, Watanabe K, Cao K.

Journal of Orthopaedic Research 35 ( 5 ) 1058 - 1066 2016

Research paper (scientific journal)

Differentiation of spinal giant cell tumors from chordomas by using a scoring system.

Tuji T, Chiba K, Watanabe K, Ishii K, Nakamura M, Nishiwaki Y, Matsumoto M.

European Journal of Orthopaedic Surgery &Traumatology 26 ( 7 ) 779-84 2016

Research paper (scientific journal)

Scoliosis is a Risk Factor for Gastroesophageal Reflux Disease in Adult Spinal Deformity.

Hosogane N, Watanabe K, Yagi M, Kaneko S, Toyama Y, Matsumoto M.

Clinical spine surgery 30 ( 4 ) E480-E484 2016

Research paper (scientific journal)

クモ膜骨化症の下位隣接椎間に生じた脊柱管狭窄症の１例

北川剛裕, 岩波明生, 三上修治, 藤田順之, 日方智宏, 渡辺航太, 石井　賢, 中村雅也, 松本守雄

東日本整形災害外科学会雑誌 28 ( 3 ) 277 2016

Research paper (scientific journal)

長期経過後に頚椎症を呈した平山病の一例

山本竜也, 日方智宏, 藤田順之, 名越慈人, 八木　満, 岩波明生, 渡辺航太, 石井　賢, 中村雅也, 松本守雄

東日本整形災害外科学会雑誌　 28 ( 3 ) 398 2016

Research paper (scientific journal)

腰・仙椎転移性脊椎腫瘍に対するMISt

日方智宏, 藤田順之, 岩波明生, 渡辺航太, 辻　崇, 中村雅也, 松本守雄

Journal of Spine Research 7 ( 8 ) 1298 - 1303 2016

Research paper (scientific journal)

思春期特発性側弯症の成人期における腰椎椎間板変性の検討

鈴木悟士, 藤原広和, 道川武紘, 藤田順之, 日方智宏, 岩波明生, 石井　賢, 中村雅也, 松本守雄, 渡辺航太

J Spine Res 7 1623 - 1627 2016

Research paper (scientific journal)

Position of the major curve influences asymmetrical trunk kinematics during gait in adolescent idiopathic scoliosis

Nishida M, Nagura T, Fujita N, Hosogane N, Tsuji T, Nakamura M, Matsumoto M, Watanabe K

Gait&Posture6 51 142-148 2016

Research paper (scientific journal)

CT-based morphological analysis of spinal fractures in patients with diffuse idiopathic skeletal hyperostosis

Okada E, Tsuji T, Shimizu K, Kato M, Fukuda K, Kaneko S, Ogawa J, Watanabe K, Ishii K, Nakamura M, Matsumoto M

Journal of orthopaedic science 22 ( 1 ) 3-9 2016

Research paper (scientific journal)

Histomorphometric analysis of minimodeling in the vertebrae in postmenopausal patients treated with anti-osteoporotic agents

Hikata T, Hasegawa T, Horiuchi K, Fujita N, Iwanami A, Watanabe K, Ishii K, Nakamura M, Amizuka N, Matsumoto M

Bone Reports 5 286 - 291 2016

Research paper (scientific journal)

【運動器疾患のゲノム解析の最前線～単一遺伝子病から、commom disease、ビックデータ解析まで～】　Commom diseaseのGWAS　思春期特発性側彎症

小倉洋二, 黄　郁代, 松本守雄, 渡辺航太, 池川志郎, 河野克己, 川上紀明, 辻　太一, 宇野耕吉, 鈴木哲平, 伊東　学, 須藤英毅, 南　昌平, 小谷俊明, 米澤郁穂, 柳田晴久, 種市　洋, 千葉一裕, 細金直文, 岡田　英次朗, 高橋洋平, 武田和樹, 日本側彎症臨床研究グループ

Clinical Calcium　 26 ( 4 ) 553 - 560 2016

Research paper (scientific journal)

【側彎症手術－術式の進歩と改善点－】前方矯正固定術　腰椎カーブに対する後方矯正固定術、前方法との比較

岡田英次朗, 渡辺航太, 松本守雄

関節外科　 35 ( 7 ) 744 - 748 2016

Research paper (scientific journal)

側彎症手術－術式の進歩と改善点－】後方矯正固定術　思春期特発性側彎症Lenke分類type1に対するshort fusion strategyによる術後肩バランスの維持

渡辺航太, 松本守雄

関節外科　 35 ( 7 ) 712 - 715 2016

Research paper (scientific journal)

II.<固定術>EXTREME LATERAL INTERBODY FUSION(XLIF) WITH PPS

石井　賢, 塩野雄太, 磯貝宜広, 船尾陽生, 細金直文, 八木　満, 日方智宏, 渡辺航太, 松本守雄

Monthly Book Orthopaedics 29 175 - 185 2016

Research paper (scientific journal)

脊髄離断術後に脊髄摘出を２回した胸髄発生Glioblastomaの1例

櫻井孝紀, 岩波明生, 藤田順之, 日方智宏, 渡辺航太, 石井　賢, 松本守雄, 中村雅也

日本脊髄障害医学会誌 29 ( 1 ) 2 - 4 2016

Research paper (scientific journal)

腰椎過前彎変形により歩行障害を呈した顔面肩甲上腕型筋ジストロフィーの１例

前田祥宏, 渡辺航太, 藤田順之, 日方智宏, 岩波明生, 石井　賢, 中村雅也, 松本守雄

関東整形災害外科学会雑誌　 47 138 2016

Research paper (scientific journal)

脊椎骨全摘術後髄液漏による胸水貯留に対して、インドシアニン・グリーン蛍光色素を用いて漏孔部を同定し修復した１例

大伴直央, 石井　賢, 藤田順之, 日方智宏, 岩波明生, 渡辺航太, 中村雅也, 松本守雄

関東整形災害外科学会誌　 47 136 2016

Research paper (scientific journal)

脊椎矢状面バランスの破綻とその対策　冠状面および矢状面での異常を伴う高度成人脊柱変形に対する手術成績と問題点.　

松本守雄, 細金直文, 渡辺航太, 八木　満, 石川雅之, 河野　仁

日本整形外科学会雑誌 89 ( 7 ) 489－494 2015.08

Research paper (scientific journal)

脊柱の変形部位が静止立位姿勢制御に及ぼす影響　思春期特発性側彎症のシングルカーブにおける検討.　

三森　由香子, 渡辺航太, 大高洋平, 藤原俊之, 細金直文, 新田　收, 長谷公隆, 松本守雄, 里宇明元

理学療法学　 42 ( 5 ) 377‐383 2015.08

Research paper (scientific journal)

腰部脊柱管狭窄症の手術成績評価におけるJOABPEQ心理ドメインに影響を与える因子．

吉岡研之, 渡辺航太, 日方智弘, 藤田順之, 岩波明生, 石井　賢, 中村雅也, 戸山芳昭, 松本守雄

Journal of Spine Research 6 ( 3 ) 760 2015.03

Research paper (scientific journal)

特発性側彎症Type5Cカーブにおける術後肩バランスの検討．

岡田英次朗, 渡辺航太, Pang Long, 小倉洋二, 高橋洋平, 日方智宏, 藤田順之, 岩波明生, 石井　賢, 中村雅也, 戸山芳昭, 松本守雄

Journal of Spine Research 6 ( 3 ) 266 2015.03

Research paper (scientific journal)

脊椎脊髄疾患に対する病態解明の現状と未来　思春期特発性側彎症に対するオーダーメード医療実現に向けた取り組み．

松本守雄, 渡辺航太, 高橋洋平, 小倉洋二, 三宅　敦, 戸山芳昭, 川上紀明, 辻　太一, 宇野耕吉, 鈴木哲平, 伊東　学, 須藤英毅, 種市　洋, 柳田晴久, 南　昌平, 小谷俊明, 河野克己, 米澤郁穂, 池川志郎, 長嶋比呂志, 梅山一大, 西脇祐司, 道川武鉱

Journal of Spine Research 6 ( 3 ) 206 2015.03

Research paper (scientific journal)

腰部脊柱管狭窄症に対する後方除圧術後の全脊柱矢状面アライメントの経時的変化と臨床成績に関する検討．

日方智弘, 渡辺航太, 藤田順之, 岩波明生, 石井　賢, 中村雅也, 戸山芳昭, 松本守雄

Journal of Spine Research 6 ( 3 ) 762 2015.03

Research paper (scientific journal)

脊索腫細胞株U-CH1-Nの椎間板研究への応用．

藤田順之, 細金直文, 石井　賢, 渡辺航太, 日方智宏, 渡邊隆一, 鈴木悟士, 堀内圭輔, 戸山芳昭, 宮本健史, 松本守雄

Journal of Spine Research 6 ( 1 ) 17－21 2015.01

Research paper (scientific journal)

Intra-and postoperative low-dose ketamine for adolescent idiopathic scoliosis surgery : a randomized controlled trail.

Minoshima R, Kosugi S, Nishimura D, Ihara N, Seki H, Yamada T, Watanabe K, Katori N, Hashiguchi S, Morisaki H.

Acta anaesthesiologica scandinavica 59 1260-8 2015

Research paper (scientific journal)

Postoperative behavior of thoracolumbar/lumbar curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis.

Ishikawa M, Cao K, Pang L, Watanabe K, Yagi M, Hosogane N, Machida M, Shiono Y, Nishiyama M, Fukui Y, Matsumoto M

Journal of Orthopaedic Science 20 31-7 2015

Research paper (scientific journal)

Scoliosis is a risk factor for gastroesophageal reflux disease in adult spinal deformity.

Hosogane N, Watanabe K, Yagi M, Kaneko S, Toyama Y, Matsumoto M

Journal of Spinal Disorders and Techniques 2015

Research paper (scientific journal)

A PAX1 enhancer locus is associated with susceptibility to idiopathic scoliosis in females.

Sharma S, Londono D, Eckalbar WL, Gao X, Zhang D, Mauldin K, Kou I, Takahashi A, Matsumoto M, Kamiya N, Murphy KK, Cornelia R; TSRHC Scoliosis Clinical Group; Japan Scoliosis Clinical Research Group, Herring JA, Burns D, Ahituv N, Ikegawa S, Gordon D, Wise CA

Nature Communications 2015

Research paper (scientific journal)

Intra- and postoperative low-dose ketamine for adolescent idiopathic scoliosis surgery: a randomized controlled trial.

Minoshima R, Kosugi S, Nishimura D, Ihara N, Seki H, Yamada T, Watanabe K, Katori N, Hashiguchi S, Morisaki H

Acta Anaesthesiologica Scandinavica 2015

Research paper (scientific journal)

脊索腫細胞株U-CH1-Nの椎間板研究への応用.

藤田順之, 細金直文, 石井賢, 渡邉航太, 日方智宏, 渡邊隆一, 鈴木悟志, 堀内圭輔, 戸山芳昭, 宮本健史, 松本守雄

Journal of Spine Research 6 17-21 2015

Research paper (scientific journal)

Surgical correction of severe kyphoscoliosis resulting in a neurological complication in Marshall–Smith syndrome.

Cao K, Watanabe K, Hosogane N, Toyama Y, Matsumoto M

Journal of Orthopaedic Science 20 430-3 2015

Research paper (scientific journal)

Metastasis of intracranial meningeal hemangiopericytoma to thoracic spine 17 years after surgical excision: a case report.

Fukuda Y, Watanabe K, Toyama Y, Mikami S, Matsumoto M

Journal of Orthopaedic Science 20 425-9 2015

Research paper (scientific journal)

Total en bloc spondylectomy for locally aggressive vertebral hemangioma causing neurological deficits.

Ogawa R, Hikata T, Mikami S, Fujita N, Iwanami A, Watanabe K, Ishii K, Nakamura M, Toyama Y, Matsumoto M

Case Reports in Orthopedics 2015

Research paper (scientific journal)

“A Novel Percutaneous Guide Wire (S-Wire) for Percutaneous Pedicle Screw Insertion: Its Development, Efficacy, and Safety”

Ishii K, Kaneko Y, Funao H, Ishihara S, Shinohara A, Nakanishi K, Hikata T, Fujita N, Iwanami A, Hosogane N, Watanabe K, Nagura T, Nakamura M, Toyama Y, Matsumoto M

Surg Innov 22 469-73 2015

Research paper (scientific journal)

“Impact of sagittal spinopelvic alignment on clinical outcomes after decompression surgery for lumbar spinal canal stenosis without coronal imbalance"

Hikata T, Watanabe K, Fujita N, Iwanami A, Hosogane H, Ishii K, Nakamura M, Toyama Y, Matsumoto M

J Neurosurg: Spine 23 451-8 2015

Research paper (scientific journal)

Impact of sagittal spinopelvic alignment on clinical outcomes after decompression surgery for lumbar spinal canal stenosis without coronal imbalance.

Watanabe K, Fujita N, Iwanami A, Hosogane N, Ishii K, Nakamura M, Toyama Y, Matsumoto M.

Journal of Neurosurgery. Spine 4 451-58 2015

Research paper (scientific journal)

Excessive reactive oxygen species are therapeutic therapeutic targets for intervertebral disc degeneration. Arthritis research & therapy 17;316, 2015.

Suzuki S, Fujita N, Hosogane N, Watanabe K, Ishii K, Toyama Y, Takubo K, Horiuchi K, Miyamoto T, Nakamura M, Matsumoto M.

Arthritis research & therapy 17 316 2015

Research paper (scientific journal)

Posterior correction and fusion surgery using pedicle-screw constructs forLenke type 5C adolescent idiopathic scoliosis: a preliminary report.

Okada E, Watanabe K, Pang L, Ogura Y, Takahashi Y, Hosogane N, Toyama Y, Matsumoto M

Spine 40 25-30 2015

Research paper (scientific journal)

Postoperative behavior of thoracolimbar/lumbar curve and coronal balance after posterior thoracic fusion forLenke 1C and 2C adolescent idiopathic scolosis.

Ishikawa M, Cao K, Pang L, Watanabe K, Yagi M, Hosogane N, Machida M, Shiono Y, Nishiyama M, Fukui Y, Matsumoto M.

Journal of Orthopaedic Science 20 31-7 2015

Research paper (scientific journal)

Surgical correction of severe kyphoscoliosis resulting in a neurological complication in Marshall-Smirh syndrome.

Cao K, Watanabe K, Hosogane N, Toyama Y, Matsumoto M.

Journal of Orthopaedic Science (JOS) 20 430-3 2015

Research paper (scientific journal)

Metastasis of intracranial meningeal hemangiopericytoma to thoracic spine 17 years after surgical excision : a case report.

Fukuda Y, Watanabe K, Toyama Y, Matsumoto M.

Journal of Orthopaedic Science (JOS) 20 425-9 2015

Research paper (scientific journal)

Posterior correction and fusion surgery using pedicle-screw constructs for Lenke type 5C adolescent idiopathic scoliosis.A preliminary report.

Okada E, Watanabe K, Pang L, Ogura Y, Takahashi Y, Hosogane N, Toyama Y, Matsumoto M

Spine 40 25-30 2015

Research paper (scientific journal)

Updates on surgical treatments for pediatric scoliosis.

Matsumoto M, Watanabe K, Hosogane N, Toyama Y

Journal of Orthopaedic Science. 19 6-14 2014

Selection of lower instrumented vertebra in treating Lenke type 2A adolescent idiopathic scoliosis.

Cao K, Watanabe K, Kawakami N, Tsuji T, Hosogane N, Yonezawa I, Machida M, Yagi M, Kaneko S, Toyama Y, Matsumoto M

Spine 39 E253-61 2014

Research paper (scientific journal)

Quantification of the spatial strain distribution of scoliosis using a thin-plate spline method.

Kiriyama Y, Watanabe K, Matsumoto M, Toyama Y, Nagura T

ournal of Biomechanics 47 302-7 2014

Research paper (scientific journal)

High preoperative hemoglobin A1c is a risk factor for surgical site infection after posterior thoracic and lumbar spinal instrumentation surgery.

Hikata T, Iwanami A, Hosogane N, Watanabe K, Ishii K, Nakamura M, Kamata M, Toyama Y, Matsumoto M

Journal of Orthopaedic Science 19 223-8 2014

Research paper (scientific journal)

Factors affecting the post operative progression of thoracic kyphosis in surgically treated adult patient with lumbar degenerative scoliosis.

Yagi M, Hosogane N, Okada E, Watanabe K, Machida M, Tezuka M, Matsumoto M, Asazuma T

Spine 39 E521-8 2014

Research paper (scientific journal)

A meta-analysis identifies adolescent idiopathic scoliosis association with LBX1 locus in multiple ethnic groups.

Londono D, Kou I, Johnson TA, Sharma S, Ogura Y, Tsunoda T, Takahashi A, Matsumoto M, Herring JA, Lam TP, Wang X, Tam EMS, Song YQ, Fan YH, Chan D, Cheah KSE, Qiu X, Jiang H, Huang D, Japanese Scoliosis Clinical Research Group, TSRHC IS Clinical Group, the International Consortium for Scoliosis Genetics, Su P, Sham P, Cheung KMC, Luk KDK, Gordon1 D, Qiu Y, Cheng J, Tang N, Ikegawa S, Wise CA

Journal of Medical Genetics 51 401-6 2014

Research paper (scientific journal)

Surgeons' exposure to radiation in single- and multi-level minimally invasive transforaminal lumbar interbody fusion; A prospective study.

Funao H, Ishii K, Momoshima S, Iwanami A, Hosogane N, Watanabe K, Nakamura M, Toyama T, Matsumoto M

PLoS One 9 e95233 2014

Research paper (scientific journal)

Association of postoperative shoulder balance with adding-on in Lenke type II adolescent idiopathic scoliosis.

Cao K, Watanabe K, Hosogane N, Toyama Y, Yonezawa I, Machida M, Yagi M, Kaneko S, Kawakami N, Tsuji T, Matsumoto M

Spine 39 E705-12 2014

Research paper (scientific journal)

Risk factors for proximal junctional kyphosis associated with dual-rod growing-rod surgery for early-onset scoliosis.

Watanabe K, Uno K, Suzuki T, Kawakami N, Tsuji T, Yanagida H, Ito M, Hirano T, Yamazaki K, Minami S, Taneichi H, Imagama S, Takeshita K, Yamamoto T, Matsumoto M

Journal of Spinal Disorders and Techniques 2014

Research paper (scientific journal)

Major complications and sequelae after total en bloc spondylectomy for malignant spinal tumors.

Matsumoto M, Hikata T, Iwanami A, Hosogane N, Watanabe K, Ishii K, Nakamura M, Toyama Y

Neurosurgery Quarterly 2014

Research paper (scientific journal)

Clinical outcome after bone, metastasis(BM) surgery in patients with differentiated thyroid carcinoma (DTC): a retrospective study of 40 cases.

Nakayama R, Horiuchi K, Susa M, Watanabe I, Watanabe K, Tsuji T, Matsumoto M, Toyama Y, Morioka H

Japanese Journal of Clinical Oncology 44 918-25 2014

Research paper (scientific journal)

Postoperative shoulder imbalance in Lenke Type 1A adolescent idiopathic scoliosis and related factors.

Matsumoto M, Watanabe K, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Yanagida H, Minami S, Akazawa T

BMC Musculoskeletal Disorders 15 366 2014

Research paper (scientific journal)

A novel percutaneous guide wire (S-Wire) for percutaneous pedicle screw insertion: Its development, efficacy, and safety.

Ishii K, Kaneko Y, Funao H, Ishihara S, Shinohara A, Nakanishi K, Hikata T, Fujita N, Iwanami A, Hosogane N, Watanabe K, Nagura T, Nakamura M, Toyama Y, Matsumoto M

Surgical Innovation 2014

Research paper (scientific journal)

Pulmonary function recovery demonstrated by ventilation-perfusion scan after posterior vertebral column resection for severe adolescent idiopathic scoliosis: a case report.

Fujii T, Watanabe K, Toyama Y, Matsumoto M

Spine 39 E1190-4 2014

Research paper (scientific journal)

Massive hemothorax caused by Gelpi retractor during posterior correction surgery for adolescent idiopathic scoliosis: a case report.

Pang L, Watanabe K, Toyama Y, Matsumoto M

Scoliosis 9 17 2014

Research paper (scientific journal)

脊椎に転移した良性転移性平滑筋腫(子宮筋腫)の1例.

野村文彦, 細金直文, 岩波明生, 辻崇, 石井賢, 中村雅也, 戸山芳昭, 千葉一裕, 松本守雄, 渡邉航太, 亀山香織, 高橋康

臨床整形外科 49 181-6 2014

Research paper (scientific journal)

拡張性胸郭形成術を併用せずVEPTR手術を行った重度乳幼児側彎症の2例.

北城雅照, 渡邉航太, 細金直文, 戸山芳昭, 松本守雄

臨床整形外科 49 743-7 2014

Research paper (scientific journal)

臨床室脊髄円錐部に発生したきわめてまれなparagangliomaの1例

畑亮輔, 石井賢, 三上修治, 渡邉航太, 戸山芳昭, 松本守雄, 中村雅也

整形外科 65 1150 -3 2014

Research paper (scientific journal)

腰部脊柱管狭窄症に対する腰椎棘突起縦割式椎弓切除術　中期成績からみた課題.

渡邉航太

整形・災害外科 57 271-4 2014

Research paper (scientific journal)

思春期特発性側弯症の全ゲノム相関解析.

松本守雄, 高橋洋平, 小倉洋二, 渡邉航太, 戸山芳昭

整形・災害外科 57 295-9 2014

Research paper (scientific journal)

特集　脊椎骨粗鬆症・圧迫骨折に対する治療戦略-薬物治療を中心に　椎体骨折を合併した腰部脊柱管狭窄症の治療　手術,薬物治療を中心に.

渡邉航太, 戸山芳昭, 松本守雄

脊椎脊髄ジャーナル 27 203-7 2014

Research paper (scientific journal)

Answer to the letter to the editor of A. Gardner concerning "Loss of apical vertebral derotation in adolescent idiopathic scoliosis: 2-year follow-up using multi-planar reconstruction computed tomography".

Watanabe K

European Spine Journal 22 22 1196-7 2013

Short fusion strategy for Lenke type 1 thoracic curve using pedicle screw fixation.

Matsumoto M, Watanabe K, Ogura Y, Okada E, Hosogane N, Chiba K, Toyama Y

Journal of Spinal Disorders and Techniques 26 93-9 2013

Research paper (scientific journal)

Total en bloc spondylectomy for spinal metastasis of differentiated thyroid cancers: a long-term follow-up.

Matsumoto M, Tsuji T, Iwanami A, Watanabe K, Hosogane N, Ishii K, Nakamura M, Morioka H, Toyama Y

Journal of Spinal Disorders and Techniques 26 E137-142 2013

Research paper (scientific journal)

A replication study for association of five single nucleotide polymorphisms with curve progression of adolescent idiopathic scoliosis in Japanese patients.

Ogura Y, Takahashi Y, Kou I, Nakajima M, Kono K, Kawakami N, Uno K, Ito M, Minami S, Yanagida H, Taneichi H, Yonezawa I, Tsuji T, Suzuki T, Sudo H, Kotani T, Watanabe K, Chiba K, Toyama Y, Matsumoto M, Ikegawa S

Spine 38 571-5 2013

Research paper (scientific journal)

Curve progression after decompression surgery in patients with mild degenerative scoliosis.

Hosogane N, Watanabe K, Kono H, Saito M, Toyama Y, Matsumoto M

ournal of Neurosurgery Spine 18 321-6 2013

Research paper (scientific journal)

Surgical correction of severe cervical kyphosis in patients with neurofibromatosis Type 1.

Kawabata S, Watanabe K, Hosogane N, Ishii K, Nakamura M, Toyama Y, Matsumoto M

Journal of Neurosurgery Spine 18 274-9 2013

Research paper (scientific journal)

Spinal coronal profiles and proximal femur bone mineral density in adolescent idiopathic scoliosis.

Chen R-Q, Watanabe K, Hosogane N, Hikata T, Iwanami A, Ishii K, Nakamura M, Toyama Y, Matsumoto M

European Spine Journal 22 2433-7 2013

Research paper (scientific journal)

Comparison of stainless steel and titanium alloy instruments in posterior correction and fusion surgery for adolescent idiopathic scoliosis-prospective cohort study with minimum 2-year follow-up.

Okada E, Watanabe K, Hosogane N, Shiono Y, Takahashi Y, Nishiwaki Y, Chiba K, Toyama Y, Matsumoto M

Journal of Medical and Biological Engineering 33 325-30 2013

Research paper (scientific journal)

A replication study for association of 53 single nucleotide polymorphisms in a scoliosis prognostic test with progression of adolescent idiopathic scoliosis in Japanese.

Spine 38 1375-9 2013

Research paper (scientific journal)

Postoperative distal adding-on and related factors in Lenke Type 1A curve.

Matsumoto M, Watanabe K, Hosogane N, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Yanagida H, Yamaguchi T, Minami S, Akazawa T

Spine 38 737-44 2013

Research paper (scientific journal)

Long-term surgical outcomes of cervical dumbbell neurinomas.

Nakamura M, Iwanami A, Tsuji O, Hosogane N, Watanabe K, Tsuji T, Ishii K, Toyama Y, Chiba K, Matsumoto M

Journal of Orthopaedic Science 13 8-13 2013

Research paper (scientific journal)

Recurrence of lumbar disc herniation after microendoscopic discectomy.

Matsumoto M, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Journal of Neurological Surgery Part A-Central European Neurosurgery 74 222-7 2013

Research paper (scientific journal)

Recurrence of lumbar disc herniation after microendoscopic discectomy.

Matsumoto M, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Journal of Neurological Surgery Part A-Central European Neurosurgery 74 222-7 2013

Research paper (scientific journal)

Recurrence of lumbar disc herniation after microendoscopic discectomy.

Matsumoto M, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Journal of Neurological Surgery Part A-Central European Neurosurgery 74 222-7 2013

Research paper (scientific journal)

Risk factors for complications associated with growing-rod surgery for early-onset scoliosis.

Watanabe K, Uno K, Suzuki T, Kawakami N, Tsuji T, Yanagida H, Ito M, Hirano T, Yamazaki K, Minami S, Kotani T, Taneichi H, Imagama S, Takeshita K, Yamamoto T, Matsumoto M

Spine 38 E464-8 2013

Research paper (scientific journal)

Identification of a susceptibility locus for severe adolescent idiopathic scoliosis on chromosome 17q24.3.

Miyake A, Kou I, Takahashi Y, Johnson TA, Ogura Y, Dai J, Qiu X, Takahashi A, Jiang H, Yan H, Kono K, Kawakami N, Uno K, Ito M, Minami S, Yanagida H, Taneichi H, Hosono N, Tsuji T, Suzuki T, Sudo H, Kotani T, Yonezawa I, Kubo M, Tsunoda T, Watanabe K, Chiba K, Toyama Y, Qiu Y, Matsumoto M, Ikegawa S

PLoS One 8 e72802 2013

Research paper (scientific journal)

Genetic variants in GPR126 are associated with adolescent idiopathic scoliosis.

Kou I, Takahashi Y, Johnson TA, Takahashi A, Guo L, Dai J, Qiu X, Sharma S, Takimoto A, Ogura Y, Jiang H, Yan H, Kono K, Kawakami N, Uno K, Ito M, Minami S, Yanagida H, Taneichi H, Hosono N, Tsuji T, Suzuki T, Sudo H, Kotani T, Yonezawa I, Londono D, Gordon D, Herring JA, Watanabe K, Chiba K, Kamatani N, Jiang Q, Hiraki Y, Kubo M, Toyama Y, Tsunoda T, Wise CA, Qiu Y, Shukunami C, Matsumoto M, Ikegawa S

Nature Genetics 45 676-9 2013

Research paper (scientific journal)

圧迫骨折を伴った腰部脊柱管狭窄症のX線画像所見の特徴と手術成績.

渡邉航太, 日方智宏, 岩波明生, 細金直文, 石井賢, 中村雅也, 戸山芳昭, 松本守雄

東日本整形災害外科学会雑誌 25 137-41 2013

Research paper (scientific journal)

薄板スプライン法を用いた側彎形状の空間的変形分布の定量化手法の開発

桐山善守, 渡邉航太, 松本守雄, 戸山芳昭, 名倉武雄

臨床バイオメカニクス 11 25-32 2013

Research paper (scientific journal)

思春期特発性側彎症患者の歩行時における下肢力学モーメントの解析

桐山善守, 渡邉航太, 細金直文, 松本守雄, 戸山芳昭, 名倉武雄

臨床バイオメカニクス 11 253-8 2013

Research paper (scientific journal)

Cervical intramedullary ependymoma masquerading as cervical spondylotic myelopathy on MRI analysis.

Tsuji O, Nakamura M, Fujiyoshi K, Ishii K, Watanabe K, Hosogane N, Tsuji T, Momoshima S, Toyama Y, Chiba K, Matsumoto M

Journal of Orthopaedic Science 18 355-8 2013

Research paper (scientific journal)

Nondura-based clear cell meningioma of the cauda equina in an adult.

Kobayashi Y, Nakamura M, Tsuji O, Iwanami A, Ishii K, Watanabe K, Hosogane N, Tsuji T, Kameyama K, Toyama Y, Chiba K, Matsumoto M

Journal of Orthopaedic Science 18 861-5 2013

Research paper (scientific journal)

Minimally invasive endoscopic resection of a solitary bone cyst of the lumbar vertebrae: a case report.

Matsubayashi K, Tsuji O, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Matsumoto M

Neurosurgery Quarterly 23 66-9 2013

Research paper (scientific journal)

Acute respiratory failure due to hemothorax after posterior correction surgery for adolescent idiopathic scoliosis: a case report.

Ogura Y, Watanabe K, Hosogane N, Toyama Y, Matsumoto M

BMC Musculoskeletal Disorders 14 132 2013

Research paper (scientific journal)

A case of skeletal tuberculosis and psoas abscess: disease activity evaluated using (18) F-fluorodeoxyglucose positron emission tomography-computed tomography.

Kimizuka Y, Ishii M, Murakami K, Ishioka K, Yagi K, Ishii K, Watanabe K, Soejima K, Betsuyaku T, Hasegawa N

BMC Medical Imaging 13 37 2013

Research paper (scientific journal)

Fontan手術後の脊柱側弯症に対し後方矯正固定術を施行した1例.

福原悠介, 渡邉航太, 前田潤, 香取信之, 戸山芳昭, 松本守雄

臨床整形外科 48 621-4 2013

Research paper (scientific journal)

神経線維腫症1型に発症した悪性末梢神経鞘腫瘍の治療成績.

中川瑠美, 須佐美知郎, 中山ロバート, 渡部逸央, 堀内圭輔, 渡邉航太, 穴澤卯圭, 戸山芳昭, 森岡秀夫.

日本レックリングハウゼン病学会雑誌 4 73-7 2013

Research paper (scientific journal)

特集筋温存型脊椎手術の現状腰部脊柱管狭窄症に対する腰椎棘突起縦割式椎弓切除術.

渡邉航太, 戸山芳昭, 松本守雄

整形・災害外科 56 233-6 2013

Research paper (scientific journal)

第1章：画像および術中解剖アトラス腰椎・腰髄腰椎後方アプローチ.

渡邉航太, 戸山芳昭, 松本守雄

脊椎脊髄ジャーナル 26 333-7 2013

Research paper (scientific journal)

Ⅱ. 小児の脊柱変形 4. Growing rod法.

渡邉航太, 戸山芳昭, 松本守雄

整形外科 64 748-52 2013

Research paper (scientific journal)

腰椎変性側彎症の手術現状と課題後方矯正固定術後のproximal junctional kyphosis.

細金直文, 渡邉航太, 戸山芳昭, 松本守雄

臨床整形外科 48 361-6 2013

Research paper (scientific journal)

Curve progression. Response.

Hosogane N, Watanabe K, Kono H, Saito M, Toyama Y, Matsumoto M

Journal of Neurosurgery Spine 18 18 320 2013

ワンポイントレクチャー腰部脊柱管狭窄症に対する腰椎棘突起縦割式椎弓切除術

渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 3 188-92 2012

Research paper (scientific journal)

上位胸椎砂時計型海綿状血管腫の1例.

鈴木悟士, 中村雅也, 渡邉航太, 辻崇, 石井賢, 戸山芳昭, 千葉一裕, 松本守雄

関東整形災害外科学会雑誌 43 149-153 2012

Research paper (scientific journal)

後方矯正固定術後に重度の冠状面off balanceを生じた成人期特発性側弯症の1例

西田光宏, 渡邉航太, 細金直文, 戸山芳昭, 千葉一裕, 松本守雄

臨床整形外科 47 1245-1249 2012

Research paper (scientific journal)

高度脊柱変形に対する手術療法の進歩重度脊柱変形の治療先天性および症候群性側彎症.

渡邉航太, 細金直文, 戸山芳昭, 千葉一裕, 松本守雄

日本整形外科学会雑誌 86 1119-24 2012

Research paper (scientific journal)

腰椎後方手術による医原性筋挫傷と術後腰痛腰椎変性所見のない馬尾腫瘍手術例での検討.

渡邉航太, 許斐恒彦, 石井賢, 中村雅也, 戸山芳昭, 松本守雄

脊椎脊髄ジャーナル 25 373-5 2012

Research paper (scientific journal)

整形外科手術私のポイント腰部脊柱管狭窄症に対する棘突起縦割式椎弓切除術.

渡邉航太, 松本守雄

整形・災害外科 55 782-3 2012

Research paper (scientific journal)

先天性多発性関節拘縮症に合併した脊柱側弯症の３例.

西山雄一郎, 渡邉航太, 細金直文, 戸山芳昭, 千葉一裕, 松本守雄

臨床整形外科 47 915-9 2012

Research paper (scientific journal)

Morphologic evaluation of the thoracic vertebrae for safe free-hand pedicle screw placement in adolescent idiopathic scoliosis: a CT-based anatomical study.

Cui G, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Lenke LG, Matsumoto M

Surgical and Radiologic Anatomy 34 209-216 2012

Research paper (scientific journal)

Safety and efficacy of linezolid in 16 infants and children in Japan.

Shinjoh M, Iketani O, Watanabe K, Shimojima N, Kudo M, Yamagishi H, Shimada H, Sugita K, Takahashi T, Mori T, Hasegawa N, Iwata S

Journal of Infection and Chemotherapy 18 591-6 2012

Research paper (scientific journal)

Transoral anterior approach using median mandibular splitting in upper spinal tumor extirpation.

Kawana H, Kato S, Asoda S, Koike A, Iwasaki R, Matsumoto M, Watanabe K, Imanishi Y, Ogawa K, Nakagawa T.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 114 E12-6 2012

Research paper (scientific journal)

Increase in spinal longitudinal length by correction surgery for adolescent idiopathic scoliosis.

Watanabe K, Hosogane N, Kawakami N, Tsuji T, Toyama Y, Chiba K, Matsumoto M

European Spine Journal 21 1920-5 2012

Research paper (scientific journal)

Impact of lamina closure on long-term outcomes of open-door laminoplasty in patients with cervical myelopathy -minimum 5-year follow-up study.

Matsumoto M, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Spine 37 1288-91 2012

Research paper (scientific journal)

Long-term surgical outcomes of spinal meningiomas.

Nakamura M, Tsuji O, Fujiyoshi K, Hosogane N, Watanabe K, Tsuji T, Ishii K, Toyama Y, Chiba K, Matsumoto M

Spine 37 E617-623 2012

Research paper (scientific journal)

Vertebral derotation in adolescent idiopathic scoliosis causes hypokyphosis of the thoracic spine.

Watanabe K, Nakamura T, Iwanami A, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Matsumoto M

BMC Musculoskeletal Disorders 13 99 2012

Research paper (scientific journal)

Sterility of posterior elements of the spine in posterior correction surgery.

Shiono Y, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Matsumoto M

Spine 37 523-6 2012

Research paper (scientific journal)

Spontaneous regression of soft disc herniation in patients with cervical myelopathy.

Matsumoto M, Okada E, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Neurosurgery Quarterly 22 7-11 2012

Research paper (scientific journal)

Changes in the cross-sectional area of deep posterior extensor muscles of the cervical spine after anterior decompression and fusion: 10-year follow-up study using MRI.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara H, Momoshima S, Nishiwaki Y, Hashimoto T, Iwanami A, Ikegami T, Takahata T

European Spine Journal 21 304-8 2012

Research paper (scientific journal)

Radiographic analysis of the progression of congenital scoliosis with rib anomalies during the growth period.

Kawakami N, Tsuji T, Yanagida H, Uno K, Matsumoto M, Watanabe K, Yamamoto T, Hirano T, Taneichi H, Yamazaki K, Fujiwara K

ArgoSpine 24 2012

Research paper (scientific journal)

Serum cartilage metabolites as biomarkers of degenerative lumbar scoliosis

Hosogane N, Watanabe K, Tsuji T, Miyamoto T, Ishii K, Niki Y, Nakamura M, Toyama Y, Chiba K, Matsumoto M

Journal of Orthopaedic Research 30 1249-53 2012

Research paper (scientific journal)

Comparative study of spinopelvic sagittal alignment between patients with and without degenerative spondylolisthesis

Funao H, Tsuji T, Hosogane N, Watanabe K, Ishii K, Nakamura M, Chiba K, Toyama Y, Matsumoto M

European Spine Journal 21 2181-7 2012

Research paper (scientific journal)

Surgical treatment of spinal extradural arachnoid cysts in the thoracolumbar spine

Funao H, Nakamura M, Hosogane N, Watanabe K, Tsuji T, Ishii K, Kamata M, Toyama Y, Chiba K, Matsumoto M

Neurosurgery 71 278-84 2012

Research paper (scientific journal)

Loss of apical vertebral derotation in adolescent idiopathic scoliosis: 2-year follow-up using multi-planar reconstruction computed tomography.

Cui G, Watanabe K (double first author), Nishiwaki Y, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Matsumoto M

European Spine Journal 21 1111-20 2012

Research paper (scientific journal)

Clinical significance of diffusion tensor tractography as a predictor of functional recovery after laminoplasty in patients with cervical compressive myelopathy.

Nakamura M, Fujiyoshi K, Tsuji O, Konomi T, Hosogane N, Watanabe K, Tsuji T, Ishii K, Momoshima S, Toyama Y

Journal of Neurosurgery Spine 17 147-152 2012

Research paper (scientific journal)

肋骨異常を伴う先天性側彎症の自然経過悪化因子の検討

川上紀明, 辻太一, 伊東学, 竹下克志, 南昌平, 宇野耕吉, 柳田晴久, 松本守雄, 渡邉航太

Journal of Spine Research 2 1750-4 2012

Research paper (scientific journal)

思春期特発性側弯症Lenke type5カーブに対する後方矯正固定術における固定範囲短縮の試み.

岡田英次朗, 渡邉航太, 小倉洋二, 高橋洋平, 細金直文, 岩波明生, 辻崇, 石井　賢, 中村雅也, 戸山芳昭, 千葉一裕, 松本守雄

臨床整形外科 47 613-618 2012

Research paper (scientific journal)

A case of spontaneous spinal epidural hematoma that mimicked acute cerebral ischemic stroke and was treated by a recombinant tissue-type plasminogen activator.

Okada E, Matsumoto M, Watanabe K, Yagi M, Ninomiya K, Horiuchi Y, Toyama Y

Neurosurgery Quarterly 22 99-101 2012

Research paper (scientific journal)

腰椎圧迫骨折後に著しい後側弯変形を呈したパーキンソン病の１治験例

山下太郎, 辻崇, 渡邉航太, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭, 松本守雄

関東整形災害外科学会雑誌 43 6-12 2012

Research paper (scientific journal)

LOVE法術後に発生した硬膜内脱出ヘルニアの1例

河野美貴子, 辻崇, 渡邉航太, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭, 松本守雄

関東整形災害外科学会雑誌 43 173-6 2012

Research paper (scientific journal)

日本側弯症学会VEPTR委員会: ワンポイントレクチャー VEPTR systemの適応と実際.

川上紀明, 辻太一, 斉藤敏樹, 野原亜也斗, 小原徹也, 宮坂和良, 佐藤貫洋, 伊藤研悠, 宇野耕吉, 松本守雄, 柳田晴久, 渡邉航太,

Journal of Spine Research 2 43-51, 2011

Research paper (scientific journal)

Wedging of vertebral bodies at the thoracolumbar junction in asymptomatic healthy subjects on magnetic resonance imaging.

Matsumoto M, Okada E, Kaneko Y, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara H, Momoshima S, Nishiwaki Y, Hashimoto T, Takahata T

Surgical and Radiologic Anatomy 33 223-8 2011

Research paper (scientific journal)

Replication study of the association between adolescent idiopathic scoliosis and two estrogen receptor genes.

Takahashi Y, Matsumoto M, Karasugi T, Watanabe K, Chiba K, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Sudo H, Minami S, Kotani T, Kono K, Yanagida H, Taneichi H, Takahashi A, Toyama Y, Ikegawa S

Journal of Orthopaedic Research 29 834-7 2011

Research paper (scientific journal)

Reduced postoperative wound pain after lumbar spinous process-splitting laminectomy for lumbar canal stenosis: a randomized controlled study.

Watanabe K, Matsumoto M, Ikegami T, Nishiwaki Y, Tsuji T, Ishii K, Ogawa Y, Takaishi H, Nakamura M, Toyama Y, Chiba K:

Journal of Neurosurgery Spine 14 51-8 2011

Research paper (scientific journal)

Remodeling of C2 facet deformity prevents recurrent subluxation in patients with chronic atlantoaxial rotatory fixation (AARF) –a novel strategy for treatment of chronic AARF

Ishii K, Matsumoto M, Momoshima S, Watanabe K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Spine 36 E256-262 2011

Research paper (scientific journal)

Lack of association between adolescent idiopathic scoliosis and previously reported single nucleotide polymorphisms in MATN1, MTNR1B, TPH1, and IGF1 in a Japanese population.

Takahashi Y, Matsumoto M, Karasugi T, Watanabe K, Chiba K, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Sudo H, Minami S, Kotani T, Kono K, Yanagida H, Taneichi H, Takahashi A, Toyama Y, Ikegawa S

Journal of Orthopaedic Research 29 1055-8 2011

Research paper (scientific journal)

Surgical treatment for scoliosis in patients with Shprintzen-Goldberg syndrome.

Watanabe K, Okada E, Kosaki K, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y, Matsumoto M

Journal of Pediatric Orthopaedics 31 186-193 2011

Research paper (scientific journal)

Late instrumentation failure after total en bloc spondylectomy.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Nakamura M, Chiba K, Toyama Y

Journal of Neurosurgery Spine 15 320-7 2011

Research paper (scientific journal)

Matrix metalloproteinase 13 in the ligamentum flavum from lumbar spinal canal stenosis patients with and without diabetes mellitus.

Cui G, Watanabe K, Miyauchi Y, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Miyamoto T, Matsumoto M

Journal of Orthopaedic Science 16 785-790 2011

Research paper (scientific journal)

Long-term surgical outcomes of idiopathic spinal cord herniation.

Nakamura M, Fujiyoshi K, Tsuji O, Watanabe K, Tsuji T, Ishii K, Matsumoto M, Toyama Y, Chiba K

Journal of Orthopaedic Science 16 347-351 2011

Research paper (scientific journal)

A genome-wide association study identifies common variants near LBX1 associated with adolescent idiopathic scoliosis.

Takahashi Y, Kou I, Takahashi A, Johnson TA, Kono K, Kawakami N, Uno K, Ito M, Minami S, Yanagida H, Taneichi H, Tsuji T, Suzuki T, Sudo H, Kotani T, Watanabe K, Chiba K, Hosono N, Kamatani N, Tsunoda T, Toyama Y, Kubo M, Matsumoto M, Ikegawa S

Nature Genetics 43 1237-1240 2011

Research paper (scientific journal)

腰椎変性すべり症に対する棘突起縦割式椎弓切除術の治療成績.

渡邉航太, 細金直文, 辻崇, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭, 松本守雄

東日本臨床整形災害外科学会雑誌 23 9-14 2011

Research paper (scientific journal)

成人特発性側弯症に対する後方矯正固定術の治療成績（30歳以上）.

渡邉航太, 細金直文, 辻崇, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭, 松本守雄

東日本臨床整形災害外科学会雑誌 23 100-3 2011

Research paper (scientific journal)

腰痛患者の現状調査

松本守雄, 渡邉航太, 細金直文, 辻崇, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭

Mebio 6 99-106 2011

Research paper (scientific journal)

特発性側彎症矯正前後における肺胸郭コンプライアンス.

小谷俊明, 南昌平, 赤澤努, 川上紀明, 辻太一, 松本守雄, 渡邉航太, 宇野耕吉, 鈴木哲平

Journal of Spine Research 2 1766-9 2011

Research paper (scientific journal)

Interpedicular graft using a titanium mesh cage in a patient with lumbar scoliosis associated with a congenital butterfly vertebra.

Cui G, Watanabe K, Ishii K, Toyama Y, Chiba K, Matsumoto M

Journal of Neurosurgery Spine 14 215-8 2011

Research paper (scientific journal)

Kyphectomy for severe kyphosis with pyogenic spondylitis associated with myelomeningocele: a case report.

Yoshioka K, Watanabe K, Toyama Y, Chiba K, Matsumoto M

Scoliosis 6 5 2011

Research paper (scientific journal)

Severe progressive scoliosis due to huge subcutaneous cavernous hemangioma: a case report.

Ogura Y, Watanabe K, Hosogane N, Tsuji T, Ishii K, Nakamura M, Toyama Y, Chiba K, Matsumoto M

Scoliosis 6 3 2011

Research paper (scientific journal)

下顎骨縦割アプローチにより全摘した軸椎骨巨細胞腫の1例

内田勲, 松本守雄, 辻崇, 渡邉航太, 石井賢, 中村雅也, 千葉一裕, 戸山芳昭

臨床整形外科 46 669-73 2011

Research paper (scientific journal)

特集高齢者の脊柱変形高齢者の腰椎変性側弯の病態と臨床像.

渡邉航太, 千葉一裕, 戸山芳昭, 松本守雄

整形・災害外科 54 109-16 2011

腰部脊柱管狭窄症に対する腰椎棘突起縦割式椎弓切除術の有効性.

渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄:

別冊整形外科 59 103-7 2011

Research paper (scientific journal)

腰部脊柱管狭窄症に対する低侵襲除圧術の問題点とその対策.

渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

整形・災害外科 54 1059-65 2011

Research paper (scientific journal)

腰部脊柱管狭窄[症]に対する手術戦略腰椎棘突起縦割式椎弓切除術.

渡邉航太, 千葉一裕

臨床整形外科 46 507-13 2011

Research paper (scientific journal)

高度脊柱変形に対する骨切り術を併用した椎弓根スクリュー法の有用性と問題点.

松本守雄, 戸山芳昭, 千葉一裕, 渡邉航太

整形・災害外科 53 53 1023-30 2010

Posterior decompression surgery for extraforaminal entrapment of the fifth lumbar spinal nerve at the lumbosacral junction.

Matsumoto M, Watanabe K, Ishii K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 12 72-81 2010

Research paper (scientific journal)

Anterior cervical decompression and fusion accelerates adjacent segment degeneration - comparison with asymptomatic volunteers in 10-year MRI follow-up study.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara H, Momoshima S, Nishiwaki Y, Iwanami A, Ikegami T, Takahata T, Hashimoto T

Spine 35 36-43 2010

Research paper (scientific journal)

Risk factors for development of subaxial subluxations following atlantoaxial arthrodesis for atlantoaxial subluxations in rheumatoid arthritis.

Ishii K, Matsumoto M, Takahashi Y, Okada E, Watanabe K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Spine 35 1551-5 2010

Research paper (scientific journal)

Adjacent segment disease and degeneration after anterior cervical decompression and fusion.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y

Neurosurgery Quarterly 20 15-22 2010

Research paper (scientific journal)

Age-related changes in thoracic and cervicalintervertebral discs in asymptomatic subjects.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara Y, Momoshima S, Nishiwaki Y, Hashimoto T, Takahata T

Spine 35 1359-64 2010

Research paper (scientific journal)

Complicated surgical resection of malignant tumors in the upper cervical spine after failed ion beam radiation therapy.

Matsumoto M, Watanabe K, Ishii K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K, Imanishi Y, Kishi K, Kawana H

Spine 35 E505-9 2010

Research paper (scientific journal)

Microendoscopic discectomy for recurrent lumbar disc herniation.

Matsumoto M, Ishii K, Watanabe K, Tsuji T, Nakamura M, Toyama Y, Chiba K

Asian Journal of Endoscopic Surgery 3 77–82 2010

Research paper (scientific journal)

Cordotomy for patients with thoracic malignant astrocytoma.

Nakamura M, Tsuji O, Fujiyoshi K, Watanabe K, Tsuji T, Ishii K, Matsumoto M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 13 418-423 2010

Research paper (scientific journal)

A novel pedicle channel classification describing osseous anatomy: how many thoracic scoliotic pedicles have cancellous channels?

Watanabe K, Lenke LG, Matsumoto M, Harimaya K, Kim YJ, Hensley M, Stobbs G, Toyama Y, Chiba K

Spine 35 1836-1842 2010

Research paper (scientific journal)

Ball tip technique for thoracic pedicle screw placement in patients with adolescent idiopathic scoliosis.

Watanabe K, Matsumoto M, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 13 246-252 2010

Research paper (scientific journal)

Microendoscopic resection of lumbar discal cysts.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K

Minimally Invasive Neurosurgery 53 69-73 2010

Research paper (scientific journal)

Microendoscopic discectomy for lumbar disc herniation in the elderly.

Matsumoto M, Ishii K, Watanabe K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Asian Journal of Endoscopic Surgery 3 174–9 2010

Research paper (scientific journal)

思春期特発性側弯症に対する後方矯正固定術におけるチタン合金製・ステンレス製instrumentの比較.

岡田英次朗, 渡邉航太, 塩野雄太, 船尾陽生, 高橋洋平, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 11 2045-9 2010

Research paper (scientific journal)

思春期特発性側弯症手術におけるrod rotationとvertebral column manipulationが肋骨隆起ならびに胸椎後弯に及ぼす影響.

船尾陽生, 渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 11 2069-73 2010

Research paper (scientific journal)

再手術を要した先天性後側彎症の1例.

岡田英次朗, 渡邉航太, 塩野雄太, 辻崇, 石井賢, 中村雅也, 戸山芳昭, 千葉一裕, 松本守雄

整形外科 61 1289-91 2010

Research paper (scientific journal)

脊髄係留を合併した先天性側弯症に対し椎体切除による脊椎後方矯正固定術を施行した1例.

高橋洋平, 渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 1 1989-93 2010

Research paper (scientific journal)

透析患者さんと腰椎疾患　－腰部脊柱管狭窄症と破壊性脊椎関節症‐.

渡邉航太, 千葉一裕

腎不全を生きる 42 42-9 2010

Research paper (scientific journal)

脊柱変形による歩行障害 Sagittal imbalanceの影響.

渡邉航太, 松本守雄, 戸山芳昭, 千葉一裕

脊椎脊髄ジャーナル 23 697－702 2010

Research paper (scientific journal)

高度脊柱変形に対する骨切り術を併用した椎弓根スクリュー法の有用性と問題点.

松本守雄, 戸山芳昭, 千葉一裕, 渡邉航太

整形・災害外科 53 1023-30 2010

Research paper (scientific journal)

Posterior decompression surgery for extraforaminal entrapment of the fifth lumbar spinal nerve at the lumbosacral junction.

Matsumoto M, Watanabe K, Ishii K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 12 12 72-81 2010

Anterior cervical decompression and fusion accelerates adjacent segment degeneration - comparison with asymptomatic volunteers in 10-year MRI follow-up study.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara H, Momoshima S, Nishiwaki Y, Iwanami A, Ikegami T, Takahata T, Hashimoto T

Spine 35 35 36-43 2010

Risk factors for development of subaxial subluxations following atlantoaxial arthrodesis for atlantoaxial subluxations in rheumatoid arthritis.

Ishii K, Matsumoto M, Takahashi Y, Okada E, Watanabe K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Spine 35 35 1551-5 2010

Adjacent segment disease and degeneration after anterior cervical decompression and fusion.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y:

Neurosurgery Quarterly 20 20 15-22 2010

Age-related changes in thoracic and cervicalintervertebral discs in asymptomatic subjects.

Matsumoto M, Okada E, Ichihara D, Watanabe K, Chiba K, Toyama Y, Fujiwara Y, Momoshima S, Nishiwaki Y, Hashimoto T, Takahata T

Spine 35 35 1359-64 2010

Complicated surgical resection of malignant tumors in the upper cervical spine after failed ion beam radiation therapy.

Matsumoto M, Watanabe K, Ishii K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K, Imanishi Y, Kishi K, Kawana H

Spine 35 35 E505-9 2010

Microendoscopic discectomy for recurrent lumbar disc herniation.

Matsumoto M, Ishii K, Watanabe K, Tsuji T, Nakamura M, Toyama Y, Chiba K

Asian Journal of Endoscopic Surgery 3 3 77–82 2010

Cordotomy for patients with thoracic malignant astrocytoma.

Nakamura M, Tsuji O, Fujiyoshi K, Watanabe K, Tsuji T, Ishii K, Matsumoto M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 13 13 418-423 2010

A novel pedicle channel classification describing osseous anatomy: how many thoracic scoliotic pedicles have cancellous channels?

Watanabe K, Lenke LG, Matsumoto M, Harimaya K, Kim YJ, Hensley M, Stobbs G, Toyama Y, Chiba K

Spine 35 35 1836-1842 2010

Ball tip technique for thoracic pedicle screw placement in patients with adolescent idiopathic scoliosis.

Watanabe K, Matsumoto M, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K

Journal of Neurosurgery Spine 13 13 246-252 2010

Microendoscopic resection of lumbar discal cysts.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K

Minimally Invasive Neurosurgery 53 53 69-73 2010

Microendoscopic discectomy for lumbar disc herniation in the elderly.

Matsumoto M, Ishii K, Watanabe K, Tsuji T, Takaishi H, Nakamura M, Toyama Y, Chiba K

Asian Journal of Endoscopic Surgery 3 3 174–9 2010

思春期特発性側弯症に対する後方矯正固定術におけるチタン合金製・ステンレス製instrumentの比較.

岡田英次朗, 渡邉航太, 塩野雄太, 船尾陽生, 高橋洋平, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 11 11 2045-9 2010

思春期特発性側弯症に対する後方矯正固定術におけるチタン合金製・ステンレス製instrumentの比較.

岡田英次朗, 渡邉航太, 塩野雄太, 船尾陽生, 高橋洋平, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 11 11 2045-9 2010

思春期特発性側弯症手術におけるrod rotationとvertebral column manipulationが肋骨隆起ならびに胸椎後弯に及ぼす影響.

船尾陽生, 渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 11 11 2069-73 2010

再手術を要した先天性後側彎症の1例.

岡田英次朗, 渡邉航太, 塩野雄太, 辻崇, 石井賢, 中村雅也, 戸山芳昭, 千葉一裕, 松本守雄

整形外科 61 61 1289-91 2010

脊髄係留を合併した先天性側弯症に対し椎体切除による脊椎後方矯正固定術を施行した1例.

高橋洋平, 渡邉航太, 戸山芳昭, 千葉一裕, 松本守雄

Journal of Spine Research 1 1 1989-93 2010

透析患者さんと腰椎疾患　－腰部脊柱管狭窄症と破壊性脊椎関節症‐.

渡邉航太, 千葉一裕

腎不全を生きる 42 42 42-9 2010

脊柱変形による歩行障害 Sagittal imbalanceの影響.

渡邉航太, 松本守雄, 戸山芳昭, 千葉一裕

脊椎脊髄ジャーナル 23 23 697－702 2010

各種疾患に伴う後彎症 Achondroplasiaによる後彎症の手術治療軟骨無形成症による胸腰椎後彎症に対する椎弓根スクリューを併用した後方骨切り術.

渡邉航太, 松本守雄, 戸山芳昭, 千葉一裕

脊椎脊髄ジャーナル 22 22 564-9 2009

Is spine deformity surgery in patients with spastic cerebral palsy truly beneficial?: a patient/parent evaluation.

Watanabe K, Lenke LG, Daubs MD, Bridwell KH, Stobbs G, Hensley M.

Spine 34 34 2222-32 2009

Clinical significance and prognosis of idiopathic syringomyelia.

Nakamura M, Ishii K, Watanabe K, Tsuji T, Matsumoto M, Toyama Y, Chiba K

Journal of Spinal Disorders and Techniques 22 22 372-5 2009

Long-term surgical outcomes for myxopapillary ependymomas of the cauda equina.

Nakamura M, Ishii K, Watanabe K, Tsuji T, Matsumoto M, Toyama Y, Chiba K

Spine 34 34 E756-60 2009

腰部脊柱管狭窄症手術例におけるこむら返りの実態調査.

松本守雄, 渡邉航太, 辻崇, 石井賢, 高石官成, 中村雅也, 戸山芳昭, 千葉一裕,西脇祐司, 道川武紘

臨床整形外科 44 44 681-6 2009

腰部脊柱管狭窄症手術例におけるこむら返りの実態調査.

松本守雄, 渡邉航太, 辻崇, 石井賢, 高石官成, 中村雅也, 戸山芳昭, 千葉一裕,西脇祐司, 道川武紘

臨床整形外科 44 44 681-6 2009

重度側彎症に対する矯正手術の治療成績 hybrid法とpedicle screw法との比較.

松本守雄, 渡邉航太, 飯塚慎吾, 戸山芳昭, 千葉一裕

臨床整形外科44 44 637-42 2009

重度側彎症に対する矯正手術の治療成績 hybrid法とpedicle screw法との比較.

松本守雄, 渡邉航太, 飯塚慎吾, 戸山芳昭, 千葉一裕

臨床整形外科44 44 637-42 2009

Progressive kyphoscoliosis associated with tethered cord treated by posterior vertebral column resection: A case report.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K

Spine 34 34 E965-8 2009

Shprintzen-Goldberg症候群に伴った側彎症の4例.

岡田英次朗, 松本守雄, 渡邉航太, 塩野雄太, 飯塚慎吾, 戸山芳昭, 千葉一裕, 小崎健次郎

臨床整形外科44 44 1063-9 2009

脊髄円錐部髄内外神経鞘腫の1治験例.

岩井宏樹, 中村雅也, 渡邉航太, 辻崇, 石井賢, 高石官成, 松本守雄, 戸山芳昭, 千葉一裕

関東整形災害外科学会雑誌 40 40 58-62 2009

治療に難渋した先天性多発性関節拘縮症に伴う脊柱後側彎症の1例.

小倉洋二, 渡邉航太, 辻崇, 石井賢, 高石官成, 中村雅也, 戸山芳昭, 千葉一裕, 松本守雄

臨床整形外科 44 44 855-60 2009

インストゥルメンテーションを併用して加療した非結核性抗酸菌症による脊椎炎の1例.

竹内弘毅, 辻崇, 渡邉航太, 石井賢, 高石官成, 中村雅也, 松本守雄, 千葉一裕, 戸山芳昭

関東整形災害外科学会雑誌40 40 148-53 2009

脊椎高位による後彎症治療の特異性腰痛・腰仙椎部後彎症腰椎形成不全性すべり症における腰仙椎後彎その病態と治療.

松本守雄, 渡邉航太, 戸山芳昭, 千葉一裕

脊椎脊髄ジャーナル 22 22 701-5 2009

イラストレイテッド・サージェリー手術編胸椎側彎症に対する椎弓根スクリュー法(ball tip probe法).

渡邉航太, 松本守雄

脊椎脊髄ジャーナル 22 22 1063-6 2009

Nocturnal leg cramps - A Common complaint in patients with lumbar spinal canal stenosis.

Matsumoto M, Watanabe, K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K, Michikawa T, Nishiwaki Y

Spine 34 34 E189-194 2009

誌上シンポジウム腰椎変性側弯症に対する術式選択の変遷とその術後成績.

千葉一裕 , 松本守雄 , 中村雅也, 高石官成, 石井賢, 辻崇, 渡邉航太, 戸山芳昭

臨床整形外科 43 43 771-7 2008

Comparison of radiographic outcomes for the treatment of scoliotic curve greater than 100 degrees: Wires vs. Hooks vs. Screws:

Watanabe K, Lenke GL, Kim YJ, Watanabe K, Kim YW, Kim YB, Hensley M, Stobbs G.

Spine 33 33 1084-1092 2008

Free hand pedicle screw placement during revision spinal surgery.

Kim YJ, Kim YW, Kim YB, Watanabe K, Watanabe K.

Spine 33 33 1141-8 2008

Surgical treatment of intramedullary spinal cord tumors: prognosis and complications.

Nakamura M, Ishii K, Watanabe K, Tsuji T, Takaishi H, Matsumoto M, Toyama Y, Chiba K

Spinal Cord 46 46 282-6 2008

Risk factors for closure of lamina after open-door laminoplasty.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Toyama Y, Chiba K.

Journal of Neurosurgery Spine 9 9 530-7 2008

手術手技私のくふう胸椎椎弓根スクリュー設置の工夫(ball tip法) 思春期特発性側彎症を対象に.

渡邉航太, 松本守雄, 飯塚慎吾, 岡田英次朗, 辻崇, 石井賢, 高石官成, 中村雅也, 戸山芳昭, 千葉一裕

臨床整形外科43 43 259-63 2008

特発性側彎症に対する胸椎椎弓根スクリュー法の短期成績従来法との比較検討.

松本守雄, 渡邉航太, 飯塚慎吾, 戸山芳昭, 千葉一裕

臨床整形外科43 43 867-73 2008

内視鏡下後方椎間板ヘルニア摘出術の中期成績.

松本守雄, 石井賢, 渡邉航太, 戸山芳昭, 千葉一裕

整形・災害外科 51 51 5-9 2008

高齢者の頸椎症・頸髄症　その診断と治療高齢者の頸椎症・頸髄症に対する頸椎・腰椎同時後方除圧術について．

渡邉航太、千葉一裕

Orthopaedics 20 20 45-51 2007

Microendoscopic discectomy for lumbar disc herniation with bony fragment due to apophyseal separation.

Matsumoto M, Watanabe K, Tsuji T, Ishii K, Takaishi H, Nakamura M, Chiba K, Toyama Y

Minimally Invasive Neurosurgery 50 50 335-9 2007

Establishment of Three-dimensional Culture of Neural Stem/Progenitor Cells in Collagen Type-1 Gel.

Watanabe K, Nakamura M, Okano H, Toyama Y.

Restorative Neurology and Neuroscience 25 25 109-17 2007

Hepatocyte growth factor promotes endogenous repair and functional recovery after spinal cord injury.

Kitamura K, Iwanami A, Nakamura M, Yamane J, Watanabe K, Suzuki Y, Miyazawa D, Shibata S, Funakoshi H, Miyatake S, Coffin RS, Nakamura T, Toyama Y, Okano H.

Journal of Neuroscience Research 85 85 2332-42 2007

Traction versus supine side-bending radiographs in determining flexibility: what factors influence these techniques?

Watanabe K, Kawakami N, Nishiwaki Y, Goto M, Tsuji T, Obara T, Imagama S, Matsumoto M.

Spine 32 32 2604-9 2007

100度以上の高度側彎症に対する手術法のX線学的評価　ワイヤー対フック対スクリュー.

渡辺慶, Lenke Lawrence G., Bridwell Keith H., Kim Yongjung J., 渡邉航太, 山崎昭義, 澤上公彦, 和泉智博

脊柱変形 22 22 124-31 2007

Becker母斑症候群に伴った側弯症の1例.

岡田英次朗, 松本守雄, 渡邉航太, 辻崇, 石井賢, 高石官成, 中村雅也, 千葉一裕, 戸山芳昭, 海老原全

臨床整形外科 42 42 819-23 2007

頸椎椎間板の加齢変化と肩凝り.

松本守雄, 渡邉航太, 千葉一裕, 戸山芳昭

ペインクリニック 28 28 159-64 2007

末梢神経系と脊髄の再生メカニズム, 脊髄の再生, 神経幹細胞移植の有効性とサル脊髄損傷モデルについて.

山根淳一, 岩波明生, 加藤裕幸, 池上健, 渡邉航太, 石井賢, 小川祐人, 中村雅也, 戸山芳昭, 谷岡功邦, 玉置憲一, 野村達次, 岡田誠司, 岡野栄之

細胞 37 37 231-4 2005

Lumbar spinous process-splitting laminectomy for lumbar canal stenosis. Technical note.

Watanabe K (corresponding), Hosoya T, Shiraishi T, Matsumoto M, Chiba K, Toyama Y

ournal of Neurosurgery Spine 3 ３ 405-8 2005

Chondroitinase ABC combined with neural stem/progenitor cell transplantation enhances graft cell migration and outgrowth of growth-associated protein-43-positive fibers after rat spinal cord injury.

Ikegami T, Nakamura M, Yamane J, Katoh H, Iwanami A, Watanabe K, Ishii K, Kato F, Fujita H, Takahashi T, Okano HJ, Toyama Y, Okano H.

European Journal of Neuroscience 22 ２２ 3036-46 2005

MRSA脊椎炎の治療経験.

渡邉航太, 松本守雄, 石井賢, 小川祐人, 高石官成, 中村雅也, 千葉一裕, 戸山芳昭

臨床整形外科 40 40 1023-8 2005

Endoscopic resection of cystic lesions in the lumbar spinal canal. A report of two cases.

Ishii K, Matsumoto M, Watanabe K, Nakamura M, Chiba K, Toyama Y

Minimally Invasive Neurosurgery 48 48 240-3 2005

Late-onset brachial plexus paresis due to subclavian pseudoaneurysm formation after clavicular fracture.

Watanabe K, Matsumura T

Journal of Trauma-Injury Infection and Critical Care 58 58 1073-4 2005

Traumatic isolated anterior dislocation of the radial head in an adult: a case report.

Watanabe K, Iwabu S, Hosoya T

Journal of Shoulder and Elbow Surgery 14 14 554-6 2005

腰部脊柱管狭窄症に対する棘突起縦割式椎弓切除術.

渡邉航太, 細谷俊彦, 白石建, 松本守雄, 千葉一裕

脊椎脊髄ジャーナル 18 18 1169-73 2005

重篤な麻痺を逃れた第8胸椎側方脱臼骨折．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

整形外科 55 55 31-4 2004

Comparison between fetal spinal cord-and forebrain-derived neural stem/progenitor cells as a source of transplantation for spinal cord injury.

Watanabe K, Nakamura M, Iwanami A, Toyama Y, Okano H

Developmental Neuroscience 26 ２６ 275-87 2004

腰部脊柱管狭窄症に対する後方支持組織を温存した「腰椎棘突起縦割式椎弓切除術」の成績（術後2年経過時）．

渡邉航太、細谷俊彦、白石建

日本脊髄障害医学会誌17 17 158－9 2004

治療に難渋したMRSAによる化膿性股関節炎の2例.

植田義之, 細谷俊彦, 渡邉航太

日本骨・関節感染症研究会雑誌 17 17 9-13, 2003

大腿骨頚部内側骨折例の人工骨頭置換術の予後について．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

整形外科54 54 1137-40 2003

腰部脊柱管狭窄症に対する後方軟部組織を温存する術式棘突起縦割式椎弓切除術．

渡邉航太、細谷俊彦、白石建:

臨床整形外科38 38 1401-6 2003

骨粗鬆症治療の検討．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍

臨床整形外科38 38 1435-7 2003

第2頚椎に発生した悪性リンパ腫の1例．

渡邉航太、細谷俊彦、小粥博樹、佐々木敏江、三笠貴彦

臨床整形外科 38 38 833-7 2003

成人男性に生じた橈骨頭の単独脱臼の1例．

渡邉航太、細谷俊彦、小粥博樹、三尾健介、城本雄一郎、植田義之、岩部昌平

日本肘関節研究会雑誌10 10 171-2 2003

左臀部に発生した原発性化膿性筋炎の1例．

渡邉航太、細谷俊彦、小粥博樹、三尾健介、城本雄一郎、植田義之

日本骨関節感染症研究会雑誌 17 17 114-7 2003

リン酸カルシウム骨ペーストによる静脈塞栓の1例.

三笠貴彦, 渡邉航太, 細谷俊彦

東日本整形災害外科学会雑誌 15 15 671-5 2003

脛骨遠位骨幹部に発生した結核性骨髄炎の1例.

三笠貴彦, 渡邉航太, 細谷俊彦

日本骨・関節感染症研究会雑誌 15 15 58-60 2002

脛骨高原骨折手術例の治療成績.

井上浩, 相羽整, 松村崇史, 吉田祐文, 八代忍, 渡邉航太, 城本雄一郎

整形外科 53 53 399-402 2002

治療に難渋している仙骨部褥瘡の1例．

渡邉航太、細谷俊彦、小粥博樹、佐々木敏江、植田義之

日本骨関節感染症研究会雑誌 16 16 19-22 2002

腰部椎間板ヘルニア術後の心因性疼痛に対して有効であった六君子湯の2例.

吉田祐文, 松村崇史, 相羽整, 八代忍, 谷田部拓, 渡邉航太

痛みと漢方 11 11 74-6 2001

当科における鎖骨骨折（中１/３）の治療成績．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

臨床整形外科36 36 877-9 2001

鎖骨遠位端骨折（Neer分類typeⅡ）の治療成績の検討．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

整形外科52 52 1180-1 2001

当科における骨粗鬆症治療の検討．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

整形外科52 52 1641-3 2001

糖尿病壊疽に対する下肢切断例．

渡邉航太、細谷俊彦、千葉和宏、谷野喜彦、三笠貴彦

日本骨関節感染症研究会雑誌15 15 80-1 2001

難治性骨折に対する超音波治療と電気刺激治療との比較.

八代忍, 松村崇史, 相羽整, 吉田祐文, 谷田部拓, 渡邉航太, 越智健介

整形外科 52 52 337-42 2001

ユニバーサルジョイント付き創外固定器による先天性橈尺骨癒合症の治療経験.

松村崇史, 相羽整, 吉田祐文, 八代忍, 谷田部拓, 渡邉航太, 越智健介

日本創外固定・骨延長学会雑誌 12 12 75-9 2001

高齢者下肢長管骨骨幹部骨折の治療経験　若年例との比較において.

谷田部拓, 松村崇史, 相羽整, 吉田祐文, 八代忍, 渡邉航太, 越智健介

骨折 23 23 628-30 2001

急激な麻痺で発症した若年者の急性脊髄硬膜外血腫の1例．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、井上浩、城本雄一郎

日本パラプレジア医学会雑誌14 14 158-9 2001

Gustilo IIIB型開放骨折後の遷延治癒骨折に対して超音波療法が有効と思われた1例.

越智健介, 松村崇史, 相羽整, 吉田祐文, 八代忍, 渡邉航太

整形・災害外科 44 44 77-80 2001

スポーツ活動により発生し短期間に消失した大腿骨異所性骨化と思われる一例

Watanabe Kouta, Takeda Tsuyoshi, Otani Toshiro, Yabe Hiroo, Toyama Yoshiaki

臨床スポーツ医学 17 ( 2 ) 245-249 2000.02

Research paper (scientific journal), Joint Work

スポーツ活動により発生し短期間に消失した大腿部異所性骨化と思われる一例

Watanabe Kouta, Takeda Tsuyoshi, Ootani Toshirou, Yabe Hiroo, Toyama Yoshiaki

臨床スポーツ医学 17 ( 2 ) 245-249 2000.02

Research paper (scientific journal), Joint Work

手根管症候群の遠位潜時の回復経過手根管開放直後よりの変化について．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、谷田部拓、越智健介

整形外科51 51 1521-3 2000

外傷性腸骨窩血腫に膿瘍が続発した1例.

渡邉航太, 市川亨, 大津寄雄志, 關美世香, 小野宏之, 石名田洋一

整形外科 51 51 1302-6 2000

外傷性腸骨窩血腫に膿瘍が続発した1例.

渡邉航太, 市川亨, 大津寄雄志, 關美世香, 小野宏之, 石名田洋一

整形外科 51 51 1302-6 2000

低出力超音波による遷延治癒骨折の治療経験.

越智健介, 松村崇史, 相羽整, 吉田祐文, 八代忍, 谷田部拓, 渡邉航太

栃木県整形外科医会会誌 14 14 34-6 2000

小児頸髄損傷患者に対する麻痺手再建の経験.

松村崇史, 相羽整, 吉田祐文, 渡邉航太, 近藤健, 近藤由実, 菅原洋子

日本パラプレジア医学会雑誌 13 13 208-9 2000

スポーツ活動により発生し短期間に消失した大腿部異所性骨化と思われる一例．

渡邉航太、竹田毅、大谷俊郎、矢部啓夫

臨床スポーツ医学 17 17 245－9 2000

外傷性腸骨窩血腫に膿瘍が続発したと思われる一例．

渡邉航太、大津寄雄志、小野宏之、関美世香、市川亨

整形外科 51 51 1302-6 2000

外傷性腸骨窩血腫に膿瘍が続発したと思われる一例．

渡邉航太、大津寄雄志、小野宏之、関美世香、市川亨

整形外科 51 51 1302-6 2000

治療に難渋した踵骨骨髄炎の2例―踵骨切除術の有用性について．

渡邉航太、松村崇史、相羽整、吉田裕文、八代忍、谷田部拓、城本雄一郎

日本骨関節感染症研究会雑誌 14 14 57-60 2000

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