Koji Tamai

Study Design: Retrospective multicenter cohort study.Purpose: This study aimed to evaluate the incidence of cage subsidence and its impact on the clinical outcomes of anterior–posterior spinal fixation (APSF) for osteoporotic vertebral fractures (OVFs). It also aimed to identify the risk factors for cage subsidence.Overview of Literature: The risk factors for cage subsidence after APSF for OVFs remain unclear.Methods: This multicenter retrospective cohort study included patients who underwent combined APSF using an expandable cage system, with a minimum 1-year follow-up at multiple centers. Patients were divided into cage subsidence (n=53) and non-subsidence (n=47) groups. Demographic data, surgery-related factors, and radiographic parameters were analyzed. After univariate analysis of factors associated with cage subsidence, multivariate logistic regression was used to identify related factors.Results: The demographic data showed a significant difference in Hounsfield unit (HU) (102.6±28.3 vs. 80.0±30.6, p=0.005) and endplate injury (p<0.001). Furthermore, 1A1B fixation was significantly more common in the subsidence group (p<0.001). Radiographic data showed significant differences in Δlocal kyphosis (supine-standing) (−7.1°±9.2° vs. −14.6°±11.5°, p=0.001). Multivariate analysis showed that Δlocal kyphosis (supine-standing) (adjusted odds ratio [aOR], 12.8; p=0.010), HU (aOR, 8.1; p=0.033), fixation range (aOR, 8.2; p=0.020), and endplate injury (aOR, 18.8; p=0.011) were significant risk factors for subsidence.Conclusions: Intraoperative endplate injury, low HU (<87.5), short fusion, and preoperative vertebral instability (Δlocal kyphosis [supinestanding] <−14) were identified as risk factors for cage subsidence in APSF. Therefore, extending the fusion levels in patients with low HU values and significant preoperative vertebral instability should be considered to avoid intraoperative endplate injury.

Study Design.: Retrospective cohort study Objective.: This study aimed to evaluate the prevalence of patient-reported bladder dysfunction in individuals with degenerative cervical myelopathy (DCM), its impact on quality of life (QOL), and postoperative bladder function and QOL improvements. Summary of Background Data.: DCM frequently causes bladder dysfunction, in addition to limb neurological deficits, which substantially impair QOL. Although it is well established that posterior decompression surgery improves neurological function, its effect on patient-reported bladder function remains unclear. Methods.: We retrospectively analyzed prospectively collected data from 163 patients who underwent cervical laminoplasty for DCM during 2019–2021. Bladder dysfunction and QOL were assessed using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), particularly its bladder dysfunction (CMEQ-BD) and QOL (CMEQ-QOL) domains. Patients with a preoperative CMEQ-BD score of 20-point increase or 2-year postoperative CMEQ-BD score of ≥90. Results.: Preoperative patient-reported bladder dysfunction was identified in 123 of the 163 patients. Compared with patients without bladder dysfunction, those with bladder dysfunction were significantly older and had worse QOL. Multivariate analysis showed that bladder dysfunction was independently associated with lower preoperative QOL (β=−0.167, P =0.031). At postoperative 2 years, only 27 of the 123 patients (22.0%) experienced postoperative bladder function improvement. No demographic or clinical factors were significantly associated with postoperative bladder function recovery. However, patients with improved bladder function showed significantly greater improvements in neurological function (JOA score, P =0.007) and QOL ( P <0.001) than those without improvement. Conclusions.: Patient-reported bladder dysfunction was highly prevalent in patients with DCM and was independently associated with impaired QOL. However, bladder dysfunction rarely improved postoperatively. These findings suggest that considering bladder dysfunction may be helpful when determining the optimal surgery timing in patients with DCM. Level of Evidence.: Level Ⅲ

Study Design: Multicenter prospective registry study. Objective: To classify patients according to whether they achieved the minimum clinically important difference (MCID) in health-related quality of life (HRQoL) after surgery for metastatic spinal tumors and to identify preoperative factors associated with clinically meaningful improvement. Summary of Background Data: As survival in patients with metastatic spinal tumors continues to improve, evaluating clinically meaningful changes in HRQoL has become increasingly important. However, factors associated with achieving clinically meaningful postoperative improvement remain unclear. Methods: Between 2018 and 2021, 413 patients undergoing surgery for metastatic spinal tumors were prospectively enrolled from 35 centers in Japan. Patients with available preoperative and 6-month postoperative EQ-5D-5L data were included in the MCID analysis (n=171). Patients were classified into the MCID improvement and non-MCID improvement groups according to the previously established MCID threshold for the EQ-5D-5L index. Patient-reported outcomes (PROs), clinical characteristics, and functional measures were compared between groups, and multivariable logistic regression analysis was performed to identify preoperative factors associated with clinically meaningful improvement. Results: Patients in the MCID improvement group demonstrated significantly greater improvements in the EQ-5D-5L index, EQ-VAS, and other PRO measures than those in the non-MCID improvement group. Compared with the non-MCID improvement group, they had poorer baseline HRQoL, poorer functional status, greater pain, and lower independence in activities of daily living. Exploratory multivariable analysis identified lower independence in dressing and greater impairment in the mobility, pain/discomfort, and anxiety/depression domains as candidate factors associated with clinically meaningful improvement. Conclusion: Patients with poorer baseline HRQoL and functional status were more likely to achieve clinically meaningful improvement after surgery for metastatic spinal tumors. These findings suggest that baseline HRQoL should be considered when interpreting postoperative outcomes and counseling patients regarding the expected benefits of surgical treatment.

... Asian Spine Journal 2026;20(4):825-826.

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A retrospective multicenter study. To determine whether the extent of intramedullary hyperintensity on initi... Asian Spine Journal 2026;():-.

Fragility fractures, which frequently occur following falls, represent a growing concern in aging populations, severely affecting health-related quality of