Hiroshi Taniwaki

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

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

Objective Osteoporosis is a well-known risk factor for incident vertebral fractures (VFs) and postoperative mechanical complications. However, the specific Hounsfield unit (HU) and vertebral bone quality (VBQ) cutoff values for predicting these complications, as well as the diagnostic and clinical significance of the differences between these two measurements, remain unclear. This study sought to evaluate the predictive value of HU and VBQ scores and to establish specific cutoff points for osteoporosis-related complications in lumbar spine surgery. Additionally, we analyzed whether combining HU and VBQ scores enhanced their predictive usefulness and whether the differences between them were clinically significant using principal component analysis (PCA). Methods We examined 189 patients with lumbar spinal stenosis who underwent microscopic bilateral decompression using a unilateral approach or short segmental fixation between 2010 and 2016. Patients who underwent prior lumbar surgery were excluded, and a minimum 5-year follow-up was conducted. Surgical indications were based on preoperative evaluation of segmental instability. HU values and VBQ scores were measured using computed tomography and magnetic resonance imaging, respectively. Osteoporosis-related complications, including incident VFs, and mechanical complications, such as proximal junctional fractures, cage subsidence, and screw loosening, were assessed. Results For predicting osteoporosis-related complications, cutoff points of HU < 95.5 and VBQ > 3.49 were identified, both demonstrating good predictive accuracy without a significant difference in the area under the curve. Multivariate logistic regression confirmed low HU and high VBQ as independent risk factors (adjusted odds ratio = 5.57 and 3.42, respectively; p < 0.001). Additionally, PCA revealed that the concordance of these scores significantly distinguished patients with complications from those without complications (odds ratio, 3.77; p < 0.001), while the differences between these scores lacked clinical significance. Conclusion This study demonstrated that both HU and VBQ scores effectively predicted postoperative osteoporosis-related complications, with no significant difference in predictive ability. Optimal cutoff values were identified at approximately ≤ 100 for HU and ≥ 3.5 for VBQ, and the difference between these two scores lacked clinical significance. These cut-offs for HU and VBQ can serve as practical thresholds for risk assessment, enabling spinal surgeons to use these scores as opportunistic tools for identifying patients at an elevated risk of osteoporosis-related complications after lumbar spine surgery.

Purpose The prevalence of adult spinal deformity (ASD) is expected to exceed 60 million by 2050 due to an aging population and increased life expectancy. Despite advances in surgery, high complication rates and the economic burden highlight the need for effective non-surgical treatments. This study assesses the “Koshimagari Exercise,” a self-exercise program for ASD patients, and aims to develop a classification system to identify those who would benefit most. Methods A prospective cohort study was conducted across 13 facilities, enrolling 144 participants from December 2020 to June 2022. The inclusion criteria were adults aged 50–80 years with chronic low back pain due to spinal deformities. Participants attended weekly physiotherapist-led exercise sessions and performed self-exercises at home three times a week, focusing on flexibility, functional improvement, trunk and back muscle strengthening, motor learning, and pain control. The primary outcome was the change in the Oswestry Disability Index (ODI) from baseline to 6 months post-intervention, with a 12-month follow-up. Clinical evaluations included health-related quality of life (HRQOL) assessments with ODI and EuroQol-5 Dimensions (EQ-5D), spinal alignment radiography, and magnetic resonance imaging of the paravertebral muscle (PVM) cross-sectional area. Results Of the 130 participants who provided written informed consent, 98 completed the 6-month follow-up. The study found that 42% of patients achieved a minimum clinically important difference (MCID) in ODI, with significant improvements in EQ-5D scores and LBP from baseline. Patients who achieved MCID had lower baseline body mass index and EQ-5D scores, and higher baseline ODI scores compared to those who did not. Logistic regression identified three significant predictors of MCID achievement: L4/S1 angle, the difference between standing and supine thoracolumbar kyphosis (ΔTLK), and the relative cross-sectional area (rCSA) of the PVM at L4/5. Based on these findings, a classification system was developed, dividing patients into Self-Exercise-Friendly and Self-Exercise-Limited groups, with a significant difference in ODI improvement observed between these groups at 6 months post-intervention. Conclusion The “Koshimagari Exercise,” a novel self-exercise program for ASD, achieved an MCID in the ODI for 42% of patients. The classification system, incorporating L4/S1 angle, ΔTLK, and L4/5 rCSA, is associated with improvements in HRQOL and may help identify patients who are more likely to benefit from this home-based exercise program.

Study Design: A retrospective study.Purpose: This study aimed to determine the impact of increased Hounsfield unit (HU) values for metastatic spinal lesions measured via computed tomography on the overall survival of patients with non-small-cell lung cancer (NSCLC) and identify factors associated with increased HU values in metastatic spinal lesions.Overview of Literature: Previous studies have underscored the utility of the HU as a marker of treatment response in metastatic bone lesions. However, no prior studies have explored the relationship between HU changes in response to treatment and overall survival in patients with NSCLC.Methods: This study included a total of 85 patients between 2016 and 2021. Nonsurgical treatments were provided by the respiratory medicine department. HU values for metastatic spinal lesions were evaluated upon diagnosis of spinal metastasis (baseline) and at 3, 6, and 12 months thereafter. Patients were then divided into two groups based on the median HU increase from baseline to 3 months. Overall survival was assessed using the Kaplan-Meier method.Results: Based on the median change in HU value (124), 42 and 43 patients were categorized into the HU responder and non-responder groups, respectively. The median overall survival was significantly longer in the HU responder group than in the HU non-responder group (13.7 months vs. 6.4 months, p <0.001). Multiple linear regression analysis revealed that the use of antiresorptive agents and molecularly targeted therapies were factors significantly associated with an increase in HU.Conclusions: An increase in HU values for metastatic spinal lesions after 3 months of treatment was correlated with a significantly longer overall survival in patients with NSCLC. Thus, HU measurements may not only serve as an easy and quantitative approach for evaluating treatment response in metastatic spinal lesions but also predict overall survival.

Background/Objective: Anti-tumor effects of plasma-activated medium (PAM) were demonstrated using various malignant tumors. However, the anti-tumor effect of PAM on synovial sarcoma remains unclear. Therefore, we aimed to investigate the anti-tumor effects of PAM on synovial sarcoma and its underlying mechanisms, focusing on the quantitative analyses of both intracellular reactive oxygen species (ROS) and cell apoptosis. Methods: The human synovial sarcoma cell line HS-SY-II was used to investigate the cell viability after PAM treatment. We investigated the anti-tumor effects and side effects of local PAM injection in a synovial sarcoma xenograft murine model. Moreover, we observed PAM-induced intracellular ROS accumulation and cell apoptosis and assessed the involvement of intracellular ROS in the anti-tumor effects of PAM using an intracellular ROS scavenger. Results: PAM significantly decreased the viability of synovial sarcoma cells compared with untreated Dulbecco’s modified Eagle medium. Local PAM injection into a synovial sarcoma xenograft murine model significantly suppressed tumor growth, including tumor volume (p < 0.001) and weight (p = 0.031), without side effects. Regarding anti-tumor mechanisms, PAM induced significant cell apoptosis and intracellular ROS accumulation (p < 0.001). The intracellular ROS scavenger significantly inhibited the anti-tumor effect of PAM (p < 0.001). Conclusions: We confirmed the anti-tumor effects of PAM on synovial sarcoma in vitro and in vivo, as well as the absence of side effects. The underlying mechanism was suggested to involve cell apoptosis induced by intracellular ROS accumulation. Considering the various clinical issues associated with the existing treatments of synovial sarcoma, PAM is a promising new option.

Objective Numerous studies have reported that corrective surgery improves postoperative health-related quality of life (HRQOL) in patients with adult spinal deformity (ASD), and postoperative HRQOL is maintained over 5-year follow-up. However, few studies have investigated factors associated with mid-term patient satisfaction. This study aimed to examine the factors contributing to 5-year patient satisfaction in patients with ASD following corrective surgery. Methods This study included 51 patients who underwent corrective surgery and were followed up for > 5 years postoperatively. We investigated radiographic parameters and patient-reported outcomes using the Scoliosis Research Society 22r (SRS-22r) questionnaire and 36-item Short-Form Health Survey (SF-36) preoperatively and at two postoperative time points: two years (PO2Y) and five years (PO5Y). Spearman's rank correlation analysis was used to assess the relationship between patient satisfaction at PO5Y and both radiographic parameters and HRQOL scores at PO2Y and PO5Y. Correlation between patient satisfaction at PO5Y and improvement of both radiographic parameters and HRQOL scores were also assessed. Results Patient satisfaction at PO5Y was significantly correlated with thoracic kyphosis, thoracolumbar kyphosis, and the distance between the C7-plumb line and the center of the sacral vertical line at PO2Y and PO5Y. Notably, the improvement of the function and social function domains of the SRS-22r and the SF-36, respectively, both at PO2Y and PO5Y, demonstrated a significantly weak correlation with patient satisfaction at PO5Y. Conclusion These findings underscore the significance of functional and social function improvements following corrective surgery, as they contribute to higher levels of satisfaction among patients with ASD.