Details of a Researcher - Watanabe, Koota

Papers - Watanabe, Koota

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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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