論文

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.

Although combination of oral and transtympanic drug therapy (CT) has been proved more effective and safer for idiopathic sudden sensorineural hearing loss (ISSNHL) by some clinical trials, there are few laboratory researches on the pharmacokinetics in the inner ear following CT on account of structural limitations of the inner ear. The aim of the present study was to investigate the pharmacokinetic behaviors of CT in the inner ear of mice. Eighteen transgenic GFAP-Luc mice which express luciferase in cochlear spiral ganglion cells were divided into oral administration (OR) group, transtympanic injection route (TT) group and CT group, and luciferin was delivered into the inner ear of these mice through oral, transtympanic or combined routes, respectively. A new in vivo imaging system was used to observe luciferin/luciferase signals and the compare the pharmacokinetics of different administration routes in the inner ear of mice. Bioluminescence signals were observed in the inner ear 3.3 ± 2.6 min after CT, significantly earlier than that of OR group (15.8 ± 7.4 min). CT owned the longest reaching-peak time and largest area under the curve (AUC) among three groups. Compared to TT, CT had longer biological half-life and higher AUC value, but did not displayed stronger peak value. There were significant differences in the peak values between OR group and TT group and between OR group and CT group. This study suggests that the OR route is less effective than the TT or CT route, and combination of OR and TT can deliver more drugs into the inner ear and confer a longer therapeutic window, but cannot increase drug intensity.

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.

Introduction: Precise prediction of hospital stay duration is essential for maximizing resource utilization during surgery. Existing lumbar spinal stenosis (LSS) surgery prediction models lack accuracy and generalizability. Machine learning can improve accuracy by considering preoperative factors. This study aimed to develop and validate a machine learning-based model for estimating hospital stay duration following decompression surgery for LSS. Methods: Data from 848 patients who underwent decompression surgery for LSS at three hospitals were examined. Twelve prediction models, using 79 preoperative variables, were developed for postoperative hospital stay estimation. The top five models were chosen. Fourteen models predicted prolonged hospital stay (!14 days), and the most accurate model was chosen. Models were validated using a randomly divided training sample (70%) and testing cohort (30%). Results: The top five models showed moderate linear correlations (0.576-0.624) between predicted and measured values in the testing sample. The ensemble of these models had moderate prediction accuracy for final length of stay (linear correlation 0.626, absolute mean error 2.26 days, standard deviation 3.45 days). The c5.0 decision tree model was the top predictor for prolonged hospital stay, with accuracies of 89.63% (training) and 87.2% (testing). Key predictors for longer stay included JOABPEQ social life domain, facility, history of vertebral fracture, diagnosis, and Visual Analogue Scale (VAS) of low back pain. Conclusions: A machine learning-based model was developed to predict postoperative hospital stay after LSS decompression surgery, using data from multiple hospital settings. Numerical prediction of length of stay was not very accurate, although favorable prediction of prolonged stay was accomplished using preoperative factors. The JOABPEQ social life domain score was the most important predictor.

Background: Accurate preoperative imaging and intraoperative pathological diagnosis are critical for managing intradural spinal tumors (IDST). This study aimed to assess the diagnostic accuracy of these methods and their impact on reoperation rates. Methods: A retrospective review was conducted on 1383 patients who underwent primary surgical treatment for IDST at a single institution between 2001 and 2022. Preoperative imaging diagnoses were established by spine surgeons and radiologists, while intraoperative pathological assessments were performed using frozen sections with hematoxylin and eosin staining in 929 cases. Final pathological diagnoses were confirmed through immunohistochemistry and genetic analysis. A diagnosis was defined as correct when the final pathology matched either of the two preoperative imaging diagnoses or the intraoperative frozen-section diagnosis. A discrepancy was recorded when the final pathology differed from both. Discrepancy assessments were determined retrospectively from medical records and pathology reports by a single investigator. The accuracy of preoperative imaging and intraoperative pathological diagnoses was compared with final pathology, and reoperation rates were analyzed. Results: The accuracy of preoperative imaging diagnosis was 94.2 %, while that of intraoperative pathological diagnosis was 93.6 %. In subgroup analyses of patients with intraoperative pathology, reoperation was more frequent in cases with inaccurate preoperative imaging compared with accurate imaging (7.7 % vs 2.2 %; P < 0.05). Similarly, intraoperative pathological discrepancies were associated with higher reoperation rates compared with concordant cases (10.2 % vs 2.1 %; P < 0.01). Conclusions: This study demonstrated that both preoperative imaging and intraoperative pathology achieved high diagnostic accuracy in IDST, generally exceeding 90 %. Subgroup analyses suggested that discrepancies in preoperative imaging as well as in intraoperative pathology may be associated with an increased risk of reoperation. These findings indicate that both reliable preoperative imaging and precise intraoperative evaluation could be important for guiding surgical management, while challenges remain in diagnosing rare and histologically diverse tumors. Level of evidence: Level III, retrospective cohort study.

Background Context: Postoperative outcomes in degenerative cervical myelopathy (DCM) vary considerably, yet few studies have characterized the heterogeneous recovery trajectories using longitudinal data. Purpose: To identify distinct postoperative quality of life (QOL) trajectories in DCM patients and determine baseline predictors of recovery patterns. Study Design/Setting: Prospective multicenter observational study. Patient Sample: A total of 977 patients undergoing surgery for DCM across 10 high-volume spine centers in Japan. Outcome Measures: The QOL outcome measure comprised the Short Form-36 physical component summary (PCS) score. Functional outcomes were specifically captured through Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire. Outcomes were measured at baseline, 6, 12, and 24 months postoperatively. Methods: Latent growth mixture modeling was employed to classify patients into distinct postoperative recovery trajectories based on PCS trends. To identify independent predictors of trajectory membership, multinomial logistic regression was performed, with variable selection refined through least absolute shrinkage and selection operator regression (LASSO) regression. Model performance was assessed using area under the receiver operating characteristic curve (AUC) for discrimination and decile-based calibration plots with bootstrap validation. Results: A total of 4 distinct PCS recovery trajectories were identified: Low-to-High (L-H, 7.3%), High-to-High (H-H, 44.9%), Low-to-Low (L-L, 37.7%), and Initial-Decline (I-D, 10.1%). Preoperative lower extremity function emerged as the strongest predictor of trajectory class, reflecting the baseline QOL. Additional significant predictors included age, smoking history, symptom duration, and cervical spine function. Particularly, reduced cervical function at baseline was found to be a significant predictor of unfavorable QOL at 24 months. The prediction model demonstrated good discriminatory performance following least absolute shrinkage and selection operator (LASSO) regression for common classes (AUCs: H-H=0.86, L-L=0.80) and moderate performance for L-H class (AUC 0.74). However, accuracy was limited for the I-D class (AUC = 0.63), and calibration was compressed in rarer classes due to class imbalance. Conclusions: Distinct patterns of postoperative recovery exist among DCM patients, with baseline physical function and patient characteristics significantly influencing QOL trajectory. While predictive models reliably distinguished major recovery patterns, less frequent trajectories, particularly those involving deterioration, were difficult to forecast. These findings support the utility of trajectory modeling and patient-reported outcome measures to enhance individualized surgical prognostication in DCM.

Study DesignProspective multicenter cohort study.ObjectiveTo evaluate the impact of surgeon experience on surgical safety, radiographic outcomes, and patient-reported outcomes (PROMs) following anterior cervical discectomy and fusion (ACDF) in patients with cervical degenerative disc disease (CDDD).MethodsThis prospective cohort study was conducted at five spine-specialized institutions in Japan. A total of 208 patients with CDDD who underwent ACDF between 2019 and 2022 were enrolled. Procedures were performed by either board-certified spine (BCS) surgeons (n = 150) or non-BCS (NBCS) surgeons (n = 58) under direct BCS supervision. Demographics, surgical variables, radiographic outcomes, and clinical results were compared. Evaluations included surgical duration, estimated blood loss (EBL), complications, cervical alignment and range of motion (ROM), Japanese Orthopaedic Association (JOA) scores, Visual Analog Scale (VAS), JOACMEQ, and SF-36 scores.ResultsSurgical duration was comparable between groups, but EBL was significantly greater in the NBCS group (20.2 ± 35.0 mL vs 12.2 ± 13.7 mL, P = .020). Complication rates were low and similar. No major adverse events occurred in either group. Cervical alignment was maintained, and ROM slightly decreased postoperatively without intergroup differences. Both groups showed significant neurological improvement. Gains in JOA scores, reductions in VAS scores, and improvements in JOACMEQ and SF-36 scores were comparable.ConclusionsACDF performed by NBCS surgeons under BCS supervision achieved clinical outcomes equivalent to those by BCS surgeons. These findings underscore the effectiveness of structured supervision in ensuring surgical safety and fostering competency in spine surgery.

Study design: Retrospective multicenter study. Objectives: To evaluate how preoperative neck pain influences clinical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL). Setting: Fourteen medical institutions in Japan. Methods: We enrolled 90 patients with cervical OPLL who underwent posterior decompression and were followed for a minimum of two years. We collected demographic data, medical history, and imaging findings. Patients were divided into two groups based on preoperative neck pain presence (Pre-op. neck pain (−) and (+) groups), and their outcomes were compared. Results: There were no significant differences in patient demographics between the Pre-op. neck pain (−) and (+) groups. Both groups showed similar distributions of ossification types and K-line positivity. Perioperative complications were comparable between the two groups. Radiographic analysis revealed no significant differences in C2–7 angles or cervical range of motion, pre- and postoperatively. Both groups demonstrated significant improvement in postoperative Japanese orthopedic association (JOA) scores, but there were no significant differences in scores or recovery rates. In the Pre-op. neck pain (−) group, factors associated with appearance of postoperative neck pain included pre- and postoperative lower JOA scores and larger C2–7 angles in neutral and extension positions. Conclusions: It emerges that lower pre- and postoperative JOA scores or larger C2–7 angles in neutral and extension positions predispose to postoperative neck pain even in those patients without preoperative neck pain. Therefore, this is worth discussing at the time of consenting patients for surgical decompression and fixation.

Study design: Retrospective comparative study Objectives: To investigate whether the presence or absence of preoperative lower extremities neurological symptoms (LENS) influences clinical outcomes following tumor resection in patients with cervical intradural extramedullary (IDEM) tumors. Setting: The single institution in Japan. Methods: Ninety-two patients with cervical IDEM tumors requiring surgical resection were included. Based on the degree of preoperative LENS assessed using the modified McCormick scale (MMCS), patients were categorized into LENS (–) and (+) groups. Demographic and surgical characteristics were compared between both groups. Results: There were no significant differences observed in sex, tumor location, tumor size, surgical time, estimated blood loss, approach for tumorectomy, or tumor histopathology between the two groups. Additionally, the overall surgical outcomes were favorable for both groups. At the final follow-up, 91.1% of the patients in the LENS (+) group were able to walk without support. Improvement in LENS was observed after surgery in most patients with preoperative MMCS II–IV, but it persisted in approximately 40% of patients with preoperative MMCS V. In the LENS (+) group, there were no significant differences in demographic or surgical data between the patients with MMCS I and II–III at the final follow-up. Conclusions: Regardless of the presence or absence of preoperative LENS, clinical improvement was observed after tumor resection in most patients with cervical IDEM tumors. These findings suggest that neurological status is likely to improve sufficiently if tumor resection is performed before preoperative LENS deteriorates to an extremely severe stage as MMCS V.

Background/Objectives: An important aspect of the pathophysiology of frailty seems to be the dysregulation of inflammatory pathways and the coagulation system. However, an objective assessment of the impact of frailty on the recovery from surgery is not fully studied. This study sought to assess how frailty affects the recovery of adult spinal deformity (ASD) surgery using blood biomarkers. Methods: 153 consecutive ASD patients (age 64 ± 10 yr, 93% female) who had corrective spine surgery in a single institution and reached 2y f/u were included. The subjects were stratified by frailty using the modified frailty index-11 (robust [R] group or prefrail and frail [F] group). Results of commonly employed laboratory tests at baseline, 1, 3, 7, and 14 post-operative days (POD) were compared. Further comparison was performed in propensity-score matched-39 paired patients between the groups by age, curve type, and baseline alignment. A correlation between HRQOLs, major complications, and biomarkers was performed. Results: Among the propensity-score matched groups, CRP was significantly elevated in the F group at POD1,3(POD1; 5.3 ± 3.1 vs. 7.9 ± 4.7 p = 0.02, POD3; 6.6 ± 4.6 vs. 8.9 ± 5.2 p = 0.02). Transaminase was also elevated in the F group at POD3(ASD: 36 ± 15 vs. 51 ± 58 U/L, p = 0.03, ALT: 32 ± 16 vs. 47 ± 55 U/L, p = 0.04). Interestingly, moderate correlation was observed between transaminase at POD1 and 2 y SRS22 (AST; function r = −0.37, mental health r = −0.39, satisfaction −0.28, total r = −0.40, ALT; function r = −0.37, satisfaction −0.34, total r = −0.39). Conclusions: Frailty affected the serum CRP and transaminase differently following ASD surgery. Transaminase at early POD was correlated with 2 y HRQOLs. These findings support the hypothesis that there is a specific physiological basis to the frailty that is characterized in part by increased inflammation and that these physiological differences persist.

Purpose: To investigate postoperative cervicothoracic sagittal alignment changes in adolescent idiopathic scoliosis (AIS) patients with thoracic lordosis and to identify radiographic predictors of cervical sagittal malalignment (CSMA). Methods: This retrospective cohort study included 72 patients with Lenke type 1 or 2 AIS with thoracic lordosis (T5–12 angle ≤ 0°) who underwent posterior spinal fusion. Radiographic parameters were evaluated preoperatively, at 1 month postoperatively (1 M), and at 2 years postoperatively (2Y). CSMA was defined as C2–7 lordosis ≤ − 10° or C2–7 sagittal vertical axis ≥ 40 mm at 2Y. Univariable and multivariable logistic regression analyses were performed to identify predictors of CSMA. Receiver operating characteristic (ROC) analysis was conducted to evaluate predictive performance and determine the optimal cutoff value of the T1 slope. Results: CSMA was observed in 30 patients (41.7%) at 2Y. Multivariable logistic regression analysis demonstrated that a lower T1 slope at 1 M was independently associated with CSMA (OR 0.87, 95% CI 0.78–0.96, p = 0.01). ROC analysis showed that T1 slope predicted CSMA with an area under the curve (AUC) of 0.76. The optimal cutoff value was 7°, with a sensitivity of 73% and a specificity of 76%. Bootstrap resampling confirmed the stability of this threshold. Patients with a T1 slope ≤ 7° had a significantly increased risk of CSMA (adjusted OR 6.95, 95% CI 2.28–21.15, p < 0.01). Conclusions: In AIS patients with thoracic lordosis, a low postoperative T1 slope was strongly associated with the development of CSMA. A T1 slope ≤ 7° at 1 month postoperatively predicted CSMA at 2 years with moderate accuracy. Achieving sufficient proximal thoracic kyphosis to maintain an adequate T1 slope may be important for preventing postoperative cervical sagittal malalignment.

Study Design: Retrospective cohort study. Purpose: To evaluate the effect of discrepancies between sacral and pelvic obliquity on postoperative disk wedging below the lower instrumented vertebra in Lenke type 5 adolescent idiopathic scoliosis (AIS). Overview of Literature: Previous studies have not fully explored the effect of discrepancies between sacral and pelvic obliquity on postoperative outcomes in patients with Lenke type 5 AIS. Methods: Data from 35 patients with Lenke type 5 AIS (mean age, 14.7±1.8 years) followed for a minimum of 5 years were retrospectively analyzed. We investigated the effect of sacral coronal obliquity (S angle) and pelvic coronal obliquity (P angle) on postoperative coronal radiographic parameters. The angle between the S and P angles was defined as the sacral and pelvic (SP) angle. The patients were grouped by preoperative SP angle (<5°, n=23; ≥5°, n=12). Pre- and post-operative radiographic parameters were compared to determine whether the preoperative SP angle affected postoperative spinal alignment. Results: The discrepancy between SP obliquity was reduced by correction surgery 5 years postoperatively. The mean lumbar Cobb angle correction rate in the ≥5° group was significantly lower than that in the <5° group (52.1%±17.8% vs. 65.5%±12.7%), and the mean wedge angle below the lower instrumented vertebra (LIV) in the ≥5° group was significantly larger than that in the <5° group (9.0°±2.6° vs. 4.7°±3.4°) 5 years postoperatively. No significant between-group differences were observed in age, Risser grade, thoracic Cobb angle correction rate, LIV-central sacral vertical line (CSVL), and C7-CSVL. The Scoliosis Research Society-22 outcomes were comparable between the two groups. Conclusions: The ≥5° group exhibited a larger wedge angle below the LIV and lower lumbar Cobb angle correction rate than the <5° group 5 years postoperatively. Preoperative discrepancies between SP obliquity should be considered when planning corrective surgery for patients with Lenke type 5 AIS.

Study Design: Retrospective multicenter study. Objectives: To investigate the impact of preoperative cervical range of motion (ROM) on clinical outcomes after posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL). Methods: We analyzed data from 156 patients with cervical OPLL who underwent posterior decompression and were followed for at least 2 years. Patients were divided into two groups based on preoperative gap ROM, which was a novel indicator representing the difference between flexion and extension ROM: the gROM <0° and >0° groups, and their outcomes were compared. Results: There were no significant differences in patient demographics or surgical details between the gROM <0° and >0° groups. The gROM <0° group exhibited less lordosis in C2-7 angles before and after surgery compared to the gROM >0° group. Cervical ROM significantly decreased following posterior decompression regardless of whether preoperative gROM was <0° or >0°. Meanwhile, the incidence of perioperative complications was similar between the two groups. Furthermore, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores postoperatively; however, there were no significant group differences in JOA scores, recovery rates, or visual analog scale for neck pain between the two groups at the preoperation and final follow-up. Conclusions: The incidence of perioperative complications and postoperative clinical outcomes were comparable regardless of the magnitude of preoperative cervical gROM. Although cervical ROM decrease postoperatively, posterior decompression for cervical OPLL can offer favorable clinical outcomes irrespective of the preoperative cervical ROM magnitude, consequently.

Introduction: Surgical interventions for cervical spine and spinal cord diseases may lead to life-threatening postoperative airway obstruction, requiring urgent airway management. This study aimed to assess the feasibility and effectiveness of our respiratory management protocol for patients undergoing anterior cervical approaches, posterior occipitocervical fusion, and intramedullary tumor resection. Methods: This single-center retrospective study consisted of 497 patients who underwent cervical surgeries, including anterior fusion, posterior occipitocervical fusion, combined anterior and posterior fusions, and intramedullary tumor resection between January 2006 and June 2022. Our institution implemented a specific postoperative airway management protocol from September 2014 onward. The protocol involved continued intubation for at least the first postoperative night, followed by a spontaneous breathing trial with a cuff leak test and extubation one or more days after surgery. We compared the outcomes between the pre-protocol period (non-protocol group, n=234) and the protocol period (protocol group, n=263). Results: There were no significant between-group differences regarding demographic, clinical, or surgical details. In the non-protocol group, four subjects required reintubation because of postoperative airway complications (anterior fusion: 1 patient, posterior occipitocervical fusion: 1 patient, and intramedullary tumor resection: 2 patients). After the airway protocol implementation, the reintubation rate dropped to zero (P=0.048). Conclusions: Our airway management protocol substantially reduced the need for reintubation. These findings emphasize the importance of postoperative respiratory management after cervical spine surgeries and underscore the need for appropriate measures to prevent complications.

Study design: Retrospective cohort study. Objectives: Due to the rarity of intradural spinal tumors (ISTs) in individuals under 20, comprehensive studies are lacking. This study aims to compare the clinical data of intramedullary and extramedullary IST cases in patients under 20 years of age with those of adult cases and to identify functional predictors that affect surgical outcomes. Setting: The single institution in Japan. Methods: This retrospective study included 1367 patients diagnosed with extramedullary or intramedullary ISTs who underwent surgery at our institution from 2001 to 2021. Patients were divided into two groups: under 20 years old (Under-20) and 20 years and older. Collected data included demographics, magnetic resonance imaging (MRI) results, and surgical and clinical information. Neurological status was evaluated using the modified McCormick Scale (mMS). Results: Among 1367 cases, 55 patients (4.0%) were under 20 years old. The most frequent tumors in the Under-20 group were astrocytoma (18.2%), followed by myxopapillary ependymoma (16.4%). Seven patients in the Under-20 group died during follow-up. Among the surviving patients, unstable gait post-surgery was associated with malignant tumors and worse preoperative mMS scores. Conclusions: This study highlights significant differences in IST epidemiology and pathology between minors and adults, emphasizing the need for early MRI to prevent paralysis progression and improve outcomes. Understanding these differences is crucial for effective diagnosis and treatment during the first two decades of life.

Objective: To determine the effects of exercise on trunk performance and balance in patients with spinal cord injury (SCI). Methods: We searched the databases MEDLINE, Cochrane Library, EMBASE, Physiotherapy Evidence Database, Web of Science, PsycINFO, and CINAHL from inception to June 2020. Our search targeted studies such as randomized or non-randomized controlled trials and randomized crossover trials that evaluated the effects of exercise on trunk performance and balance in patients with SCI. Results: Seventeen eligible studies with 432 patients with SCI were included in the meta-analysis. The exercise significantly improved several measures: Berg Balance Scale (mean differences [MD] = 4.58; 95% confidence intervals [CI], 0.35, 8.8; p = 0.03), Modified Functional Reach Test (MD = 5.29; 95% CI, 4.16, 6.42; p < 0.01), T-shirt test (MD = 5.62; 95% CI, − 3.82, − 7.42; p < 0.01), Timed Up and Go (MD = − 1.70; 95% CI, − 0.23, − 3.16; p = 0.02). Improvements were also noted in total static sitting balance (standardized mean differences [SMD] = 1.21; 95% CI, 0.79, 1.63; p < 0.01), and total dynamic sitting balance (SMD = 1.01; 95% CI, 0.30, 1.73; p < 0.01). In the subgroup analysis, exercise with sensory input enhancement significantly improved total static (SMD = 1.37; 95% CI, 0.64, 2.11; p < 0.01) and total dynamic sitting balance (SMD = 1.78; 95% CI, 0.28, 3.29; p = 0.02). Conclusions: Exercise may improve sitting balance in patients with SCI. Moreover, enhancement of sensory input had an add-on effect in improving sitting balance. Registration: PROSPERO (CRD42020185904).