Published papers

Study design: Single-institution retrospective study. Objectives: To assess postoperative functional and quality of life (QOL) outcomes in elderly patients who underwent cervical spinal cord tumor surgery using the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). Setting: Single university hospital. Methods: This retrospective study included 97 patients who underwent surgery for cervical spinal cord tumors between 2000 and 2016. Patients were divided into two groups: a younger group (patients < 65 years old) and an elderly group (patients ≥ 65 years old). Surgical outcomes were evaluated using JOA scores and JOACMEQ, with statistical comparisons between age (younger vs. elderly) and tumor types (intramedullary vs. extramedullary). Results: Preoperative JOA scores were significantly lower in the elderly group compared to the younger group. Postoperative recovery rates were similar between the two groups. Extramedullary tumor resections in the elderly showed notable functional improvements. Conversely, elderly patients with intramedullary tumors exhibited poorer outcomes in lower extremity function and QOL, as measured by the JOACMEQ. Conclusion: Surgical intervention for cervical spinal cord tumors in elderly patients can yield functional and QOL outcomes similar to those in younger patients, especially for extramedullary tumors. However, intramedullary tumor resections in the elderly may result in less favorable outcomes, particularly in lower limb function and QOL. These findings underscore the importance of thorough preoperative counseling for elderly patients, highlighting potential risks and benefits based on tumor type.

Study design: Retrospective cohort study Objectives: Ventrally located cervical spinal meningiomas present significant surgical challenges due to their proximity to the spinal cord and nerve roots. This study aimed to evaluate the surgical outcomes of these tumors resected via the posterior approach and to compare them with dorsolaterally located meningiomas. Setting: The single institution in Japan. Methods: A retrospective review was conducted on 39 patients who underwent posterior surgical resection of cervical spinal meningiomas between 2008 and 2023, with a minimum follow-up of one year. Patients were classified into ventral (n = 17) and dorsolateral (n = 22) groups based on tumor localization. Neurological function was assessed using the Japanese Orthopedic Association (JOA) score, and surgical outcomes were compared. Results: The groups had no significant differences in operative time or blood loss. However, nerve root resection was significantly more frequent in the ventral group (41.2 vs. 9.1%, p = 0.02), and perioperative complications and intraoperative motor-evoked potential amplitude reduction (35.3 vs. 4.5%, p = 0.03) were more common (41.2 vs. 13.6%, p = 0.06). Although postoperative JOA scores were lower in the ventral group (14.6 ± 0.6 vs. 16.4 ± 0.3, p = 0.01), both groups showed significant postoperative improvement compared to preoperative scores (p < 0.01). Conclusions: Despite the higher risk of nerve root sacrifice and limited neurological recovery associated with the posterior approach, considering the functional improvements from baseline, it remains a viable surgical option for ventrally located cervical meningiomas. Further studies comparing different surgical approaches are needed to optimize treatment strategies.

Study Design. A retrospective multicenter study. Objectives. To analyze symptom-specific surgical outcomes in patients with mild degenerative cervical myelopathy (DCM) and identify predictors of postoperative residual symptoms. Summary of Background Data. DCM is the most common cause of spinal cord impairment in adults. While surgical intervention is recommended for moderate to severe DCM, optimal treatment strategies for mild DCM remain unclear. Previous studies have focused on total Japanese Orthopaedic Association (JOA)/modified JOA (mJOA) score without detailed symptom-specific analyses. Methods. We reviewed 679 consecutive patients who underwent surgical decompression with or without fusion for DCM across three institutions in Japan. Among them, 104 patients with mild DCM (JOA score 14.5-16.5) were included. We assessed demographic data, radiographic factors, magnetic resonance imaging parameters, and clinical scores. Symptom-specific analyses were conducted using preoperative and 2-year postoperative JOA scores, and the predictors of persistent symptoms were analyzed using multivariable logistic regression. Results. The mean maximum canal compromise was 49.7%, and maximum spinal cord compression was 37.2%. The most common factors leading to surgery was symptom deterioration (94.2%). In symptom-specific analysis, 60.9% of patients exhibited persistent upper extremity sensory impairment, significantly higher than other domains. Multivariable analysis identified angular-edged deformity of the spinal cord on axial MRI as an independent predictor of persistent upper extremity sensory impairment (Odds Ratio: 4.264, 95% confidence interval: 1.312-13.854, P=0.016). Conclusion. The majority of mild DCM patients who underwent surgery had severe spinal cord compression, with symptom progression serving as the trigger for surgical intervention. While surgical intervention improves overall function, upper extremity sensory impairments frequently persisted postoperatively, even in mild cases. Angular-edged deformity was a significant predictor for postoperative upper extremity sensory deficits, emphasizing the need for careful preoperative evaluation of spinal cord morphology to better inform prognosis and guide treatment decisions in patients with mild DCM.

Study Design: Retrospective Cohort Study. Objective: Modic changes (MCs) have been associated with low back pain; however, their prognostic value in surgical outcomes—particularly in patients with lumbar spinal stenosis (LSS) treated with decompression alone—remains unclear. Few studies have investigated the progression and long-term clinical impact of MCs. This study aimed to evaluate the 10-year progression of MCs and their association with clinical outcomes following posterior decompression surgery for LSS. Methods: This study included 62 patients who underwent posterior decompression for LSS and completed a 10-year follow-up with MRI and clinical assessments. MCs and disc degeneration were evaluated using standardized MRI criteria. Japanese Orthopaedic Association (JOA) scores and recovery rates were assessed preoperatively and at follow-up. Outcomes were compared between Modic-negative patients and those with preoperative Modic Type 1 or Type 2 changes. Analysis of covariance adjusted for confounding variables. Results: The prevalence of MCs increased from 37.1% preoperatively to 74.2% at 10 years. Type 1 changes were dynamic, often progressing to Type 2 or 3. Type 2 changes were more stable and associated with significantly lower postoperative JOA scores and recovery rates compared to Modic-negative or Type 1 patients (P < 0.05), after adjustment for age, sex, sagittal alignment parameters, and disc degeneration. Type 2 MCs were also linked with minimal improvement in back pain. Conclusion: Modic changes, particularly Type 2, are associated with inferior long-term outcomes. These findings suggest that Modic Type 2 may serve as a prognostic marker of advanced degeneration and may be associated with reduced recovery following decompression surgery.

Study Design. Retrospective case series. Objective. The aim of this study was to compare the outcomes of posterior decompression surgery for lumbar spinal canal stenosis (LSS) in patients with preoperative sagittal malalignment (MA) with those without, after adjusting for age and sex. Summary of Background Data. Sagittal balance is an important factor in spine surgery and is thought to affect postoperative outcomes after LSS. However, the relationship between sagittal MA and postoperative outcomes has not been thoroughly examined. Patients and Methods. We included 533 patients who underwent surgical treatment for LSS and also achieved 2-year follow-up. Patients were categorized into either an MA+ group (69 patients) or a matched-alignment (MA-) group (348 patients) based on age-adjusted preoperative sagittal alignment. We compared the baseline and 2-year postoperative health-related quality of life (HRQOL) using the Visual Analog Scale and Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores. We also calculated clinical efficacy using the minimal clinically important difference based on JOABPEQ scores, and age and sex-adjusted JOABPEQ scores 2 years after surgery. Differences between groups were examined using the Mann-Whitney U test and χ2 analysis, where applicable. Results. Both groups showed an improved HRQOL after decompression surgery. Similar proportions of patients showed substantial improvement, as estimated by the minimal clinically important difference, in 4 out of 5 subdomains of the JOABPEQ. A significantly smaller proportion of patients in the MA+ group showed substantial improvement in lumbar function. The age and sex-adjusted HRQOL scores 2 years after surgery were lower in the MA+ group, particularly in the lumbar function and social life function subdomains of the JOABPEQ. Conclusion. The effects of posterior decompression surgery alone can still be observed at least 2 years postoperatively for patients with LSS and concomitant sagittal MA. Patients with sagittal MA may experience lower HRQOL than those without this type of MA.

Cell-based therapy targeting spinal cord injury (SCI) is an attractive approach to promote functional recovery by replacing damaged tissue. We and other groups have reported the effectiveness of transplanting neural stem/progenitor cells (NS/PCs) derived from human induced pluripotent stem cells (hiPSCs) in SCI animal models for neuronal replacement. Glial replacement is an additional approach for tissue repair; however, the lack of robust procedures to drive iPSCs into NS/PCs which can produce glial cells has hindered the development of glial cell transplantation for the restoration of neuronal functions after SCI. Here, we established a method to generate NS/PCs with gliogenic competence (gNS/PCs) optimized for clinical relevance and utilized them as a source of therapeutic NS/PCs for SCI. We could successfully generate gNS/PCs from clinically relevant hiPSCs, which efficiently produced astrocytes and oligodendrocytes in vitro. We also performed comparison between gNS/PCs and neurogenic NS/PCs based on single cell RNA-seq analysis and found that gNS/PCs were distinguished by expression of several transcription factors including HEY2 and NFIB. After gNS/PC transplantation, the graft did not exhibit tumor-like tissue formation, indicating the safety of them as a source of cell therapy. Importantly, the gNS/PCs triggered functional recovery in an SCI animal model, with remyelination of demyelinated axons and improved motor function. Given the inherent safety of gNS/PCs and favorable outcomes observed after their transplantation, cell-based medicine using the gNS/PCs-induction procedure described here together with clinically relevant iPSCs is realistic and would be beneficial for SCI patients.

Study Design: Prospective multicenter cohort study. Objectives: Although surgery for degenerative cervical myelopathy (DCM) often improves neurological function, predicting clinically meaningful recovery remains challenging. To identify preoperative predictors of achieving the minimum clinically important difference (MCID) in the Japanese Orthopaedic Association (JOA) score and to evaluate its association with patient-reported outcomes. Methods: We prospectively analyzed 762 patients with moderate to severe DCM (defined by preoperative JOA score <15) who underwent surgery at 10 high-volume centers in Japan, with a 2-year follow-up. MCID was defined as a ≥2.5-point improvement in JOA score. Logistic regression identified independent predictors. Outcomes included JOA score, Visual Analog Scale (VAS), the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the 36-Item Short Form Health Survey (SF-36). Results: MCID was achieved in 63.0% of patients. Independent predictors included younger age (Odds ratio = 0.973 [95% confidence interval: 0.956-0.990]; P = 0.002), absence of cerebrovascular (0.466 [0.224-0.960]; P = 0.039) and cardiac disease (0.510 [0.285-0.912]; P = 0.023), greater cervical lordosis (1.021 [1.004-1.037]; P = 0.013), lower baseline JOA score (0.547 [0.485-0.617]; P < 0.001), and higher JOACMEQ scores for upper extremity function (1.011 [1.000-1.022]; P = 0.044) and QOL (1.021 [1.009-1.033]; P < 0.001). MCID achievement was associated with significantly greater improvements in VAS, most JOACMEQ domains, and all SF-36 subscales. Conclusions: Younger age, absence of cerebrovascular and cardiac disease, greater cervical lordosis, lower baseline JOA score, and higher preoperative JOACMEQ scores for upper extremity function and QOL were associated with achieving MCID in JOA score.

Background: Surgical strategies for spinal deformities associated with neurofibromatosis type 1(NF-1) have been still controversial due to the wide variety of pathologies, particularly, for deformities with severe dystrophic changes in pediatric patients remained challenging with high complication and reoperation rates. The purpose of this study was to validate our surgical strategies by evaluating clinical and radiographical outcomes. Methods: We retrospectively evaluated 22 cases who underwent correction surgeries for spinal deformities in our institute. The investigations included patient background, presence of dystrophic changes and paravertebral tumors, surgical procedure, number of surgeries, complications and reoperation, and radiographical parameters including Cobb angle and T1-S1 length. Results: The mean age at the first surgery was 11.6 ± 5.5 years. The mean follows up period was 84.3 ± 50.2 months. Of the 22 cases, 4 cases had cervical kyphosis and 18 cases had deformity in thoracic and/or lumbar spine. Dystrophic changes of spine were observed in all 4 cases with cervical kyphosis and 15 cases with spinal deformity in thoracic and/or lumbar spine. All cases with cervical kyphosis underwent posteroanterior fusion following halo gravity traction preoperatively. The mean local kyphosis of cervical spine improved from 83.7 ± 5.9° to 16.9 ± 2.4° after surgery and 19.4 ± 2.5° at final follow up, and 2 cases required unplanned surgery due to pseudarthrosis. In cases of deformity in thoracic and/or lumbar spine, 11 cases underwent posteroanterior fusion, 4 cases underwent only posterior fusion, and 3 cases underwent conventional growing-rod, of which 4 cases underwent halo gravity traction before correction surgery. The mean Cobb angle of scoliosis in thoracic and/or lumbar spine improved from 73.2 ± 16.9° to 30.9 ± 15.8° after surgery and 29.5 ± 13.3° at final follow up, and that of T1-S1 growth increased from 338.3 ± 13.3 mm to 406.3 ± 8.9 mm at final follow up. Four cases required unplanned surgery due to pseudarthrosis (n = 2) or progression of deformity (n = 2). Conclusion: The fundamental of surgical treatment for NF-1-related spinal deformity is extensive rigid spinal fusion by adequate bone grafting. Even if these surgeries are performed, in some cases additional surgery could be necessary due to progression of deformity. Level of Evidence: Level III, retrospective cohort study.

Study Design: Retrospective comparative study. Objectives: This study aimed to determine whether the severity of preoperative gait disturbance remains after surgical resection in patients with intramedullary spinal cord tumors (IMSCTs), and to identify any factors influencing poor improvement in postoperative gait disturbance. Methods: The study included a total of 128 patients with IMSCTs requiring surgical excision between 2006 and 2019. Based on the degree of preoperative gait disturbance assessed by the modified McCormick scale (MMCS) grade, patients were categorized into Mild (I-II) and Severe (III-V) groups. The mean postoperative follow-up period was 55.5 ± 34.3 months, and demographic and surgical characteristics were compared between the two groups. Results: Significant differences were observed in age at surgery, tumor location, tumor size, estimated blood loss, intraoperative motor-evoked potential disappearance, extent of resection, and tumor histopathology between the Mild and Severe groups. In the Mild group, at the final follow-up, only 7.3% of patients experienced improvement, 56.0% showed no changes, and 36.7% experienced deterioration. Conversely, in the Severe group, 26.3% of patients experienced improvement, 31.6% showed no changes, and 42.1% experienced deterioration. Tumor location and age at surgery were identified as factors correlated with poor improvement in postoperative gait disturbance in the Mild group. Conclusions: Irrespective of the preoperative gait disturbance degree, approximately 40% of patients with IMSCTs experienced deterioration in gait after tumor resection. For preoperative MMCS grade I-II cases, older age at surgery and thoracic IMSCTs would be important factors associated with poor improvement in postoperative gait disturbance.

Background: Few studies have examined the changes in cervical sagittal alignment (CSA) and its relationship with other sagittal alignments in AIS patients with major thoracolumbar/lumbar (TL/L) curve who underwent correction surgery. This study investigated the radiographical changes in CSA after correction surgery in patients with Lenke type 6 adolescent idiopathic scoliosis (AIS) and assess any possible factors affecting postoperative CSA. Methods: Forty-four patients with Lenke type 6 AIS (3 males and 41 females, mean age at surgery of 15.6 ± 2.8 years) who could be followed up for 3 years after correction surgery were included in this study. Variations of outcome variables were analyzed in various spinal sagittal parameters using radiographic outcomes. Univariate correlation analyses were used to evaluate possible factors influencing the postoperative CSA. The Scoliosis Research Society (SRS)-22 questionnaires and the Oswestry Disability Index (ODI) were used for clinical evaluation, and the changes between pre- and 3-year post-operation were compared. Results: The Cobb angle of the major and minor curve was significantly improved after correction surgery. Furthermore, CSA, such as C2-7 angle and T1 slope, changed significantly postoperatively. The magnitude of coronal curve correction did not affect CSA postoperatively, while the postoperative TK, T10-L2 kyphosis and LL were significantly correlated with the postoperative C2-7 angle, respectively. None of the patients in this study complained of neck or low back pain during the period up 3 years after the operation. Comparing each domain of SRS-22 or ODI score, these were unchanged between pre-, 1-year, and 3-year post-operation, with no statistically significant differences. Conclusions: CSA changed significantly after correction surgery, and cervical kyphosis indicated a tendency to decrease in Lenke type 6 AIS patients, which was associated with an improvement in thoracic and lumbar sagittal alignment, not correction for coronal deformity.

Purpose: Intradural spinal metastases, including intramedullary (IM) and intradural extramedullary (IDEM) lesions, are rare manifestations of advanced systemic malignancy, and the role of surgery remains controversial. This study aimed to clarify how anatomical compartments influence surgical intent, feasibility, and postoperative neurological outcomes. Methods: We retrospectively reviewed fifteen consecutive patients who underwent surgery for intradural spinal metastases between 2010 and 2024. Lesions were classified as IM (n = 6) or IDEM (n = 9). Clinical presentation, operative characteristics, extent of resection, and adjuvant therapy were evaluated. Neurological function was assessed using the modified McCormick scale (MMCS) before and after surgery. Results: IM lesions were more frequently associated with severe preoperative neurological impairment and were predominantly located in the thoracic spine, whereas IDEM lesions were distributed across cervical, thoracic, and lumbar levels. Gross total resection was achieved more often in IDEM lesions (44.4%) than in IM lesions (16.7%). Postoperatively, neurological function improved in 5 patients (33.3%), remained stable in 6 (40.0%), and deteriorated in 4 (26.7%). Although improvement occurred in both groups, IDEM lesions more often achieved a favorable final functional status (MMCS grades I–II), whereas IM lesions frequently showed limited functional recovery. No perioperative complications were observed. Conclusions: Surgical intervention for intradural spinal metastases may be considered selectively as part of a multidisciplinary palliative strategy focused on neurological function. Anatomical compartment influences surgical feasibility, intent, and achievable outcomes. IDEM lesions may allow resection with functional recovery in selected patients, whereas IM lesions generally require a conservative, function-preserving approach with clearly defined goals.

Objective: This study examined radiographic changes in local and global spinal alignments and clinical outcomes following tumor resection without spinal fixation in patients with lumbar dumbbell tumors (LDTs). Methods: We included 28 patients with LDTs who were followed for at least 2 years after surgery. We analyzed variations in the outcome variables by measuring individual coronal and sagittal parameters from radiographs. Clinical outcomes were assessed using the modified McCormick scale, the Japanese Orthopedic Association score, and the visual analog scale. To evaluate the impact of tumor location on these outcomes, we categorized the patients into 3 groups based on tumor location: upper (T12–L1), middle (L2–3), or lower (L4–S1) group. Results: The local and global spinal parameters (including Cobb angle, cervical lordosis, T1 slope, thoracic kyphosis, thoracolumbar kyphosis, lumbar lordosis [global, upper, middle, lower], sacral slope, pelvic incidence, and pelvic tilt) did not show significant changes after surgery. Preoperatively, all patients experienced gait disturbances, but at the final follow-up, nearly all of them (27 cases, 96.4%) could walk without support. The Japanese Orthopedic Association score and visual analog scale demonstrated significant postoperative improvements. There were no statistically significant group differences in postoperative coronal and sagittal profiles or clinical outcomes among the upper, middle, and lower groups. Conclusions: Tumor resection without spinal fixation had no substantial impact on local and global spinal alignments and led to satisfactory clinical outcomes, suggesting that spinal fixation may not always be necessary when resecting LDTs.

Study Design. A prospective multicenter cohort study. Objective. To identify clinical indicators associated with postoperative functional and quality-of-life (QOL) outcomes in patients with degenerative cervical myelopathy (DCM), using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). Summary of Background Data. Although surgical intervention is the standard treatment for DCM, a subset of patients experience suboptimal postoperative outcomes. The specific impact of surgical treatment on various physical functions in patients with DCM remains inadequately understood. Materials and Methods. A total of 935 DCM patients were prospectively enrolled and were followed up for 2 years across 10 institutions in Japan. Of these, 852 patients with complete JOACMEQ data were included. Preoperative and postoperative assessments at 2 years included JOA score, visual analog scale, and JOACMEQ. Logistic regression analyses were conducted to identify indicators of effective outcomes across JOACMEQ domains. Results. Surgical intervention led to significant improvements in JOA scores and pain reduction. Effective rates by the JOACMEQ domain were 49.6% (cervical function), 48.5% (upper extremity), 35.1% (lower extremity), 23.2% (bladder), and 23.8% (QOL). Multivariate analysis revealed that better cervical function was associated with lower body mass index (BMI) and reduced neck pain at 2 years. Shorter symptom duration and upper limb pain improvement predicted better upper extremity outcomes. Younger age, shorter symptom duration, and reduced lower limb pain were linked to improved lower extremity function. Bladder function was negatively affected by longer symptom duration. Lower QOL was associated with longer symptom duration, cardiovascular comorbidities, and persistent neck and upper limb pain at final follow-up. Conclusion. Surgical intervention for DCM generally improves neurological function and pain. However, JOACMEQ analysis reveals that factors such as disease duration, residual pain, age, and BMI significantly influence physical function and QOL. These findings highlight the importance of surgical timing and adequate informed consent to optimize outcomes in DCM patients.

Study design: A retrospective cohort study. Objectives: While numerous studies have investigated surgical outcomes for cervical spondylosis, limited research has examined the impact of surgical techniques in patients with unilateral upper extremity proximal muscle weakness. This study compares clinical outcomes between anterior cervical decompression and fusion (ACDF) and posterior decompression (PD) with foraminotomy in patients with cervical spondylosis presenting with unilateral proximal muscle weakness. Methods: This study included 45 patients diagnosed with either cervical spondylotic amyotrophy (CSA) or cervical spondylotic radiculopathy (CSR) with unilateral proximal muscle weakness. Twenty CSA and five CSR patients underwent ACDF (anterior group), whereas 16 CSA and four CSR patients underwent PD with foraminotomy (posterior group). Muscle strength was assessed using the Manual Muscle Test (MMT) in the most improved muscle. Preoperative and postoperative MMT scores, Japanese Orthopaedic Association (JOA) scores, and imaging findings were analyzed. Results: The mean age at surgery was 63.2 years in the anterior group and 61.3 years in the posterior group (p = 0.31). No significant differences were observed in preoperative MMT (2.0 vs. 2.1, p = 0.75), JOA scores (13.9 vs. 13.5, p = 0.60), or C2–C7 angles (2.3° vs. −0.9°, p = 0.55). Postoperative JOA scores (15.6 vs. 15.1, p = 0.19) and C2–C7 angles (3.0° vs. 3.9°, p = 0.78) were comparable. Both groups showed significant improvement in MMT (p < 0.01); however, the difference in improvement between the ACDF and PD groups (2.5 vs. 1.9) did not reach statistical significance (p = 0.06). Conclusions: Postoperative outcomes were similarly favorable for both ACDF and PD with foraminotomy, suggesting that each procedure represents an effective treatment option for cervical spondylotic disease presenting with unilateral proximal upper limb muscle weakness.

Study Design: A retrospective comparative study. Objectives: To clarify the distinctive magnetic resonance imaging (MRI) features and surgical outcomes of intramedullary schwannoma (IMS) compared to extramedullary schwannoma (EMS) in the spinal cord. Setting: Hospital in Tokyo, Japan. Methods: 19 cases each of IMS and EMS were matched by propensity score from a cohort of spinal cord tumor patients treated between 2008 and 2022. Preoperative MRI images were meticulously analyzed for general values and distinctive features at the tumor-spinal cord interface. Surgical outcomes were assessed based on neurological function, visual analogue scale (VAS), and recurrence rates. Results: IMS and EMS exhibited similar MRI intensity patterns on T1- and T2-weighted images, but differed significantly in features surrounding the tumor, such as rough boarder (IMS: 78.9%, EMS: 5.3%, P value < 0.001) and peritumoral edema (IMS: 57.9%, EMS: 10.5%, P value = 0.005). Postoperatively, IMS cases showed substantial neurological improvement, with no recurrences following gross total resection (GTR). However, residual pain at the segmental level persisted more commonly in IMS compared to EMS (postoperative VAS, IMS: 45.0 ± 34.3, EMS: 19.7 ± 26.8, P value = 0.017). Conclusions: The distinct MRI features identified, particularly the observation of the border with the spinal cord, offer valuable insights for differentiating IMS from EMS preoperatively. Although IMS results in improved neurological function with no recurrence following GTR, attention must be given to residual pain.

Study Design: Retrospective comparative study. Objectives: To compare surgical and clinical outcomes of thoracic intradural extramedullary (IDEM) meningiomas based on tumor location, specifically between ventral and dorsal/lateral lesions. Methods: This study retrospectively analyzed 60 consecutive patients who underwent posterior surgical resection for thoracic IDEM meningiomas at a single institution between 2007 and 2022. Patients were stratified into two groups according to tumor location on preoperative MRI: Ventral group (n = 23) and Dorsal/Lateral group (n = 37). Clinical outcomes were assessed using the modified McCormick scale (MMCS). Surgical parameters and complications were also compared. Results: Patients in the Ventral group had significantly larger sagittal tumor diameters and higher spinal canal occupancy rates than those in the Dorsal/Lateral group (p < 0.05). Preoperative motor deficits were more frequent in the Ventral group (86.9 vs. 51.3%, p < 0.01). Estimated blood loss was greater in the Ventral group (p = 0.01). Intraoperative motor evoked potential deterioration occurred more often (p = 0.04). Although both groups showed neurological improvement postoperatively, the percentage of patients reaching MMCS Grade I at final follow-up was significantly lower in the Ventral group (17.3 vs. 54.0%, p < 0.01). No tumor recurrence was observed in either group during the follow-up period (mean: 61.4 months). Conclusions: Ventrally located thoracic IDEM meningiomas are associated with more severe preoperative motor dysfunction and inferior postoperative neurological recovery compared to dorsal/lateral lesions. These findings highlight the importance of early surgical intervention and tailored surgical planning for ventral tumors to optimize functional outcomes.

Study Design: Retrospective multicenter study. Objectives: To investigate surgical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. Methods: We included 203 patients with cervical OPLL who were followed for a minimum of 1 year after surgery. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed preoperatively and at the final follow-up using the Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) for the neck. We compared outcomes between BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and NBCS surgeons. Results: BCS surgeons performed 124 out of 203 cases, while NBCS surgeons were primary in 79 cases, with 73.4% were directly supervised by a BCS surgeon. There was no statistically significant difference in surgical duration, estimated blood loss, and perioperative complication rates between the BCS and NBCS groups. Moreover, no statistically significant group differences were observed in each position of the C2-7 angle and cervical range of motion at preoperation and the final follow-up. Preoperative and final follow-up JOA scores, VAS for the neck, and JOA score recovery rate were comparable between the two groups. Conclusions: Surgical outcomes, including functional recovery, complication rates, and cervical dynamics, were comparable between the BCS and NBCS groups. Consequently, posterior decompression for cervical OPLL is considered safe and effective when conducted by junior surgeons who have undergone training and supervision by experienced spine surgeons.

Study Design: Multicenter, prospective cohort study. Objective: To compare the clinical outcomes of three posterior decompression techniques—open-door (OD) laminoplasty, double-door (DD) laminoplasty, and selective laminectomy (SL)—in patients with degenerative cervical myelopathy (DCM). Summary of Background Data: Although OD, DD, and SL are widely used for DCM, prospective comparative studies evaluating all three techniques in a large-scale cohort remain limited. Methods: This study included 759 patients with DCM (OD: n = 214; DD: n = 157; SL: n = 388) who underwent posterior decompression without fusion across 10 high-volume institutions in Japan. Clinical outcomes were assessed at baseline and 2 years postoperatively using the cervical Japanese Orthopaedic Association (JOA) score, SF-36, visual analog scale (VAS), and JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). Cervical alignment and range of motion (ROM) were evaluated radiographically. A general linear model and multivariable logistic regression were used to compare outcomes after adjusting for relevant confounders. Results: All groups showed significant postoperative improvement in JOA scores exceeding the minimal clinically important difference (MCID), with no significant differences among the groups. Similar improvements were observed in SF-36, VAS, and JOACMEQ domains. SL demonstrated significantly better preservation of cervical ROM at two years compared to OD and DD. The incidence of perioperative complications did not significantly differ among the three techniques. Conclusion: OD, DD, and SL provided comparable neurological recovery, functional improvement, and pain relief in patients with DCM. Although SL demonstrated superior preservation of cervical mobility, all three techniques were similarly safe and effective. Therefore, the choice of surgical procedure should be guided by the surgeon’s experience, institutional protocols, and the clinical characteristics of each case.