Abstract Study design A retrospective case control study Objective To predict proximal junctional kyphosis (PJK) risk by normalizing individual vertebral bone strength using the ratio of vertebral Hounsfield unit (HU) values around the upper instrumented vertebrae (UIV). Summary of background data PJK poses a significant challenge in treating patients after adult spinal deformity (ASD) surgery. While the vertebral body HU value is associated with PJK risk, the optimal threshold remains unclear, and a relative assessment of HU values within individuals has not been conducted. Methods Data on patients who underwent corrective fusion of the middle to lower thoracic region of the pelvis for ASD were assessed. The 126 patients were categorized into PJK and non-PJK groups. We compared the patients’ backgrounds, vertebral body HU, and junctional HU ratio, defined as the HU value of UIV+1 divided by the HU value of UIV (HU UIV+1 /HU UIV ). The UIV+2/UIV+1 HU ratio was calculated similarly. Results The PJK and non-PJK groups included 30 and 96 patients, respectively. After propensity score matching, 28 patients from each group were analyzed. HU values at UIV+2 and UIV+1 (117.0 ± 46.6 vs 145.1 ± 45.9, p=0.018, and 105.5 ± 36.2 vs 147.3 ± 44.9, p<0.001, respectively) were lower in the PJK group. Junctional HU ratio was significantly lower in the PJK group (0.88 ± 0.18 vs 1.13 ± 0.25, p<0.001), and receiver operating characteristic analysis showed that the junctional HU ratio had the highest discriminative ability (area under the curve 0.812). At the optimal cutoff value (HU ratio of 0.905), the sensitivity and specificity for PJK were 64.3% and 89.3%, respectively. Conclusions A low junctional HU ratio was strongly associated with PJK after ASD surgery. This parameter reflects the bone strength mismatch at the proximal junction and may help improve preoperative risk assessment and UIV selection.

Study DesignRetrospective cohort study.ObjectivesSurgery for adult spinal deformity (ASD) is associated with postoperative mechanical complications (MCs), such as proximal junctional kyphosis (PJK). The applicability of the Global Alignment and Proportion (GAP) score for predicting MCs in older Asians remains unclear. This study aimed to evaluate the validity of the GAP score in Asians patients by stratifying them into younger and older groups.MethodsWe studied 274 patients who had undergone multi-level spinal fusion and were followed up for at least 2 years. Patients were divided into a younger group (Under-69, n = 122) and an older group (Over-70, n = 152). MCs were assessed at 2 years postoperatively. Propensity score matching was performed to compare the incidence of MCs across groups. Logistic regression models were used to examine the interaction between GAP score and age.ResultsMC occurred in 93 patients (34%), with no significant differences between groups. In the Under-69 group, GAP scores did not correlate with MC occurrence. In contrast, the in the Over-70 group patients with MCs had significantly lower GAP scores (6.6 ± 3.4 vs. 8.0 ± 3.2, P = 0.022). The interaction between GAP score and age was not significant in the logistic regression models.ConclusionsThe GAP score demonstrated limited predictive ability for MCs in this Asian ASD cohort, particularly in older patients. These findings suggest that alignment-based prediction models alone may be insufficient for MC risk stratification in aging populations.

INTRODUCTION:While physical function and health-related quality of life (HRQOL) are recognized as important factors in aging, evidence regarding their long-term associations remains limited. This study investigated whether baseline physical function measures predict HRQOL after 8 years in community-dwelling adults. METHODS:We conducted a longitudinal analysis of data from community health checkups in rural Japan. Of 678 baseline participants (2012-2014), 130 adults (mean age 62.1 ± 7.7 years, 52.3% female) with complete follow-up data were analyzed. Physical function was assessed using the Timed Up & Go Test (TUG), 10-m gait time, grip strength, and back muscle strength. HRQOL was measured using the SF-36 questionnaire. Multivariable linear regression analyses examined associations between baseline physical function and 8-year follow-up HRQOL, adjusting for baseline HRQOL and covariates. RESULTS:Cross-sectional associations at baseline were limited. However, longitudinal analyses revealed robust associations. After adjustment, TUG was significantly associated with follow-up Physical Functioning (B = -3.53, p = 0.021), Role-Physical (B = -11.40, p < 0.001), Social Functioning (B = -6.20, p < 0.001), Role-Emotional (B = -7.69, p < 0.001), and Mental Health (B = -6.28, p < 0.001). The 10-m gait time showed similar associations. Muscle strength measures were primarily associated with Bodily Pain outcomes. CONCLUSIONS:Baseline locomotive measures, particularly TUG and gait speed, independently predict multiple HRQOL domains after 8 years. These simple assessments during routine checkups may identify individuals at risk for long-term HRQOL decline, supporting early preventive interventions.

Large multicenter prospective study. We aimed to develop and validate a novel machine learning-based prognostic scoring system for spinal metastases. Spinal metastases, common complications in patients with advanced cancer, significantly affect neurological function, pain, and quality of life. Although surgery plays a crucial role in selected cases, the accurate prediction of patient prognosis remains challenging. Traditional scoring systems, developed for older treatment paradigms, do not fully reflect the impact of modern oncologic therapies. This multicenter prospective study, conducted by the Japan Association of Spine Surgeons with Ambition, included 401 patients who underwent surgery for spinal metastases at 35 medical centers between 2018 and 2021. Patient demographics, tumor burden, performance status, and treatment history data were collected. Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression was used to identify significant predictors of one-year survival, followed by stepwise variable selection. The model performance was assessed using the area under the receiver operating characteristic curve (AUROC) and calibration plots. Among the 401 patients, 67.1% survived for one year, whereas 32.9% did not. Survivors had better performance status, lower tumor burden, and lower opioid use than non-survivors. LASSO regression identified five key predictors of one-year survival: age ≥75 years, poor performance status (≥3), presence of other bone metastases, preoperative opioid use, and lower preoperative Vitality Index. The final model demonstrated a strong predictive performance (AUROC=0.762). Based on the key prognostic factors, a simplified risk stratification system was developed to classify patients into low- (one-year survival 82.2%), intermediate- (67.2%), and high-risk (34.2%) groups. We developed a clinically applicable prognostic scoring system for patients with spinal metastases using machine learning techniques to enhance predictive accuracy. This model provides a practical risk assessment tool to aid surgical decision-making and optimize postoperative management. 2

STUDY DESIGN:Multicenter prospective cohort study; secondary analysis. OBJECTIVE:To evaluate predictors associated with 1-year survival after surgery for spinal metastases by comparing a comprehensive 50-variable deep learning (DL) model with a previously published 5-variable LASSO-based machine learning (ML) model and applying DL-based permutation feature importance as an exploratory analytic lens. SUMMARY OF BACKGROUND DATA:Surgical decision-making for spinal metastases requires reliable survival estimates. Traditional scores such as those of Tokuhashi and Tomita and contemporary tools such as SORG and NESMS support prognostication, but performance and calibration may vary across cohorts. A parsimonious 5-variable JASA ML model is clinically practical, whereas DL may help identify prognostic signals embedded in detailed activities of daily living (ADLs), patient-reported outcomes (PROs), and scoring-system components. METHODS:We analyzed 401 complete-case patients who underwent surgery for spinal metastases at 35 Japanese institutions (2018-2021). A feed-forward neural network incorporating 50 preoperative variables was evaluated using five repeated random 8:2 train-test splits. Accuracy, AUROC, Brier score, and calibration summaries were reported and descriptively compared with the previously published 5-variable LASSO-based ML model. RESULTS:At 1 year, 269 of 401 patients were alive. The DL model achieved 75.5+/- 3.0% accuracy (95% confidence interval [CI], 71.8%-79.2%), held-out AUROC 0.789 (95% CI, 0.681-0.886), and Brier score 0.214. The ML model achieved 71.8% accuracy (Wilson 95% CI, 67.2%-76.0%) and apparent AUROC 0.762. Because the comparison was descriptive rather than paired, formal statistical superiority was not claimed. DL feature importance highlighted Vitality Index-On and Off Toilet, EQ-5D-5L total score and pain/discomfort, and individual Tokuhashi/Tomita components; the ML-selected Vitality Index-Wake Up item ranked 38th. CONCLUSIONS:The 50-variable DL model provided reasonable prediction and generated clinically plausible feature-importance hypotheses, but it did not demonstrate a clearly meaningful performance advantage over the simpler 5-variable ML model. DL may be most useful for research-based feature discovery and refinement of future parsimonious prognostic tools, whereas validated simple models remain more practical for bedside prognostication. LEVEL OF EVIDENCE:2.

Lumbosacral fusion (LSF) is the standard approach in adult spinal deformity (ASD) surgery but is frequently associated with proximal junctional kyphosis. Floating fusion (FF) has been proposed as an alternative approach. This study examined factors influencing the selection of FF and identified postoperative adverse factors associated with each surgical approach. This multicenter study retrospectively reviewed the records of patients who underwent surgery for ASD. They were divided into FF and LSF groups and compared by baseline patient characteristics and radiological parameters. Each group was further divided and compared according to mechanical complications (MC). The number of fusion levels (odds ratio [OR] = 0.50, 95

STUDY DESIGN:Large multicenter prospective study. OBJECTIVE:We aimed to develop and validate a novel machine learning-based prognostic scoring system for spinal metastases. SUMMARY OF BACKGROUND DATA:Spinal metastases, common complications in patients with advanced cancer, significantly affect neurological function, pain, and quality of life. Although surgery plays a crucial role in selected cases, the accurate prediction of patient prognosis remains challenging. Traditional scoring systems, developed for older treatment paradigms, do not fully reflect the impact of modern oncologic therapies. METHODS:This multicenter prospective study, conducted by the Japan Association of Spine Surgeons with Ambition, included 401 patients who underwent surgery for spinal metastases at 35 medical centers between 2018 and 2021. Patient demographics, tumor burden, performance status, and treatment history data were collected. Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression was used to identify significant predictors of one-year survival, followed by stepwise variable selection. The model performance was assessed using the area under the receiver operating characteristic curve (AUROC) and calibration plots. RESULTS:Among the 401 patients, 67.1% survived for one year, whereas 32.9% did not. Survivors had better performance status, lower tumor burden, and lower opioid use than non-survivors. LASSO regression identified five key predictors of one-year survival: age older than or equal to 75 years, poor performance status (≥3), presence of other bone metastases, preoperative opioid use, and lower preoperative Vitality Index. The final model demonstrated a strong predictive performance (AUROC=0.762). On the basis of the key prognostic factors, a simplified risk-stratification system was developed to classify patients into low-risk (one-year survival 82.2%), intermediate-risk (67.2%), and high-risk (34.2%) groups. CONCLUSIONS:We developed a clinically applicable prognostic scoring system for patients with spinal metastases using machine learning techniques to enhance predictive accuracy. This model provides a practical risk assessment tool to aid surgical decision-making and optimize postoperative management. LEVEL OF EVIDENCE:Level II.

Background: The Global Alignment and Proportion score has been validated in surgical cohorts as a predictor of mechanical complications in adult spine deformity, but its significance in the general population is poorly understood. We examined the association of the Global Alignment and Proportion score categories with locomotor syndrome and health-related quality of life in community-dwelling middle-aged and older adults to clarify the role of proportionality of sagittal alignment in musculoskeletal function and quality of life. Methods: Residents of Hokkaido, Japan, who underwent musculoskeletal health screening in 2019 were included in this retrospective cross-sectional study. Based on their Global Alignment and Proportion score classification, participants were divided into three groups: proportioned, moderately disproportioned (moderate), and severely disproportioned (severe). We compared participants' background, bone mineral density, exercise tests, pain levels, locomotor syndrome stage, and Short Form 36-Item Health Survey score data. Results: The mean age of the 217 participants was 64.0±9.5 years; 127 were female. The mean Global Alignment and Proportion score was 6.1±3.4 points, and the proportioned, moderate, and severe groups comprised 27, 106, and 84 participants, respectively. A statistically significant trend was observed in which the number of participants at high risk for locomotive syndrome increased as the Global Alignment and Proportion risk state worsened. In the Short Form 36 Health Survey domains of bodily pain and physical component summary scores, statistically significant trends toward lower scores were observed across groups with worsening Global Alignment and Proportion risk status. Conclusions: We identified an association between poorer Global Alignment and Proportion scores and the presence of locomotive syndrome, as well as lower health-related quality of life, among middle-aged and older adults. These findings suggest that the Global Alignment and Proportion score may be a useful indicator for characterizing musculoskeletal alignment in clinical and public health fields.

This study aimed to assess longitudinal changes in spinal alignment and range of motion (ROM) across different age groups over 10 years, focusing on thoracic kyphosis (TK), lumbar lordosis (LL), and spinal inclination angle (SIA), identify key inflection points in age-related spinal changes, and explore their clinical implications for maintaining postural control and preventing falls in older adults. This was a longitudinal cohort study including 96 healthy adult participants who underwent spinal assessments during 2007–2009 and 2017–2019 as part of an annual health checkup. Spinal alignment and ROM were measured using SpinalMouse® in upright standing and dynamic flexion/extension postures. TK (T1–T12), LL (L1–S1), and SIA were assessed using radiography. TK (T1–T12) significantly increased from 38.9° ± 10.3° to 41.3° ± 9.9° (p < 0.01), whereas LL (L1–S1) significantly decreased from 21.8° ± 9.9° to 18.6° ± 11.2° (p < 0.01). The SIA increased significantly, indicating a forward-shifted posture. Flexion ROM slightly increased in the thoracic spine (T5–T12), but extension ROM significantly decreased in the upper thoracic region (T1–T5), reflecting age-related spinal rigidity. This study revealed significant age-related changes in spinal alignment and ROM over 10 years, particularly the increase in TK, reduction in LL, and decline in extension ROM. These findings may support the potential value of early interventions aimed at preserving spinal flexibility and posture, though further research is needed to confirm their effectiveness in improving outcomes.

Objectives: This study investigated the potential of Hounsfield unit (HU) values obtained from computed tomography (CT) scans as predictors of mechanical complications (MCs) in patients undergoing long-segment spinal fusion involving the pelvis. Additionally, it identified a threshold HU value associated with an increased risk of MCs. Methods: We conducted a retrospective, multicenter review of patients who underwent long-segment spinal fusion involving the pelvis, with a minimum follow-up period of two years. Patients were categorized based on the presence or absence of postoperative MCs. Both preoperative and postoperative radiographic parameters were analyzed, and HU values were quantified from CT images. Logistic regression modeling was used to identify independent risk factors for MCs. Results: Among 129 patients, 33 (25.6%) developed MCs, including proximal and distal junctional failures, rod fractures, and cases necessitating re-operation. The HU values were significantly lower in the MC group, whereas conventional bone mineral density (BMD) measurements showed no significant difference. Global alignment parameters, such as the sagittal vertical axis (SVA) and global tilt (GT), were consistently higher in patients with MCs. Receiver operating characteristic analysis identified 131 HU as the optimal cut-off, yielding a sensitivity of 56.4% and a specificity of 69.7%. Multivariate analysis confirmed that lower HU values were independently associated with the occurrence of MCs. Conclusions: Lower HU values and larger radiological global alignment parameters are significant predictors of MCs in patients undergoing surgery for adult spinal deformity. These findings underscore the importance of CT-based quantitative assessments in preoperative planning.

Introduction:This study aimed to identify the factors associated with the postoperative deterioration of sagittal balance after surgery for adult spinal deformity (ASD), focusing on preoperative alignment and pelvic incidence (PI). Methods:We retrospectively reviewed the medical records of 87 patients who underwent corrective surgery for ASD (2017-2020). Sagittal balance was assessed using the sagittal balance classification (SBC). The patients were classified as balanced (maintained SBC grade 1 or 2) or imbalanced (deteriorated to grade 3). Radiographic parameters, clinical outcomes (Japanese Orthopedics Association scores and mechanical complications), and bone mineral density were analyzed. Results:In 15 patients (17.2%), the sagittal balance deteriorated to grade 3 (imbalanced group). Factors significantly associated with postoperative deterioration of sagittal balance included preoperative grade 3 SBC (73.3% vs. 23.6%, p<0.001), steroid use (26.7% vs. 2.8%, p<0.01), pelvic fusion (80% vs. 51.4%, p=0.049), higher preoperative PI, sacral slope, and sagittal vertical axis. At 2 years, the imbalanced group showed a significantly greater corrective loss of the lumbar spine. Receiver operating curve analysis identified preoperative PI ≥52.1° as predictive of postoperative imbalance (sensitivity 86.7%, specificity 66.7%). The clinical outcomes were similar, but the reoperation rates were higher in the imbalanced group (20.0% vs. 2.8%, p=0.03). Conclusions:High preoperative PI, severe sagittal imbalance, steroid use, and pelvic fusion were predictive of postoperative sagittal balance deterioration, underscoring the need for personalized preoperative planning.

Study Design A cross-sectional study. Purpose To determine the effectiveness of the pelvic ring ratio as an indicator for assessing pelvic tilt (PT) from the frontal view and explore its correlation with various whole-body sagittal alignment (WBSA) parameters using EOS imaging technology. Overview of Literature Traditional indicators of PT often rely on sagittal plane measurements, which can be challenging in cases of pelvic rotation or obesity. A new indicator such as the pelvic ring ratio could address these challenges and aid in the comprehensive assessment of pelvic alignment. Methods In total, 104 healthy participants (28 men, 76 women; mean age, 52.8±12.3 years) with no spinal disorders were recruited. Whole-body radiography using the EOS imaging system was performed to obtain sagittal and coronal parameters, including the pelvic ring ratio. Intra- and interobserver variability were assessed using intraclass correlation coefficients (ICCs) based on measurements by three spine surgery specialists. Correlation analyses among the pelvic ring ratio, age, body mass index, and WBSA parameters were conducted, and a multiple linear regression model was developed to predict PT. Results The mean pelvic ring ratio was 53.3%±11.5%. The intra- and interobserver ICCs were 0.89 and 0.87, respectively, indicating good reliability. The pelvic ring ratio was negatively correlated with age (r=−0.387, p<0.05) and PT (r=−0.598, p<0.05). The regression model revealed that the pelvic ring ratio and sex significantly predicted PT (p<0.05). Women had higher pelvic ring ratio (55.0%±11.3%) than men (48.6%±10.8%). Conclusions The pelvic ring ratio is a reliable and valuable indicator for PT assessment from the frontal view. It exhibits significant correlations with age and certain WBSA parameters, showing potential to improving the diagnostic accuracy and treatment planning for patients with spinal and hip disorders.

The adoption of lumbar fusion techniques, particularly lateral lumbar interbody fusion (LLIF), has significantly evolved the management of degenerative lumbar spinal conditions. LLIF, introduced as a minimally invasive surgical procedure, offers the advantage of indirect neural decompression and robust bone fusion using large interbody cages, reducing complications such as cage subsidence and nerve injuries. Systematic reviews have indicated that LLIF was effective for foraminal decompression, although evidence regarding its effectiveness for spinal canal and lateral recess decompression remains limited. Comparisons between indirect decompression techniques like LLIF and direct methods (posterior lumbar interbody fusion and transforaminal lumbar interbody fusion) have revealed that while indirect approaches generally promoted lower surgical times and blood loss, outcomes related to pain, disability, and complications were comparable. Indirect decompression with LLIF should be approached cautiously or avoided in patients with severe stenosis or preoperative neurological impairments due to the increased risk for postoperative complications. Furthermore, meticulous surgical planning and advanced imaging techniques are essential for mitigating risks such as vascular, bowel, and ureteral injuries. Continued advancements in surgical instrumentation and navigation technologies are expected to further refine the utility of LLIF in treating complex spinal pathologies, offering a promising minimally invasive option for achieving effective spinal stabilization and decompression.

Study Design Retrospective cohort study. Objectives Successful bone fusion is crucial for favorable posterior lumbar interbody fusion (PLIF) outcomes. While trabecular bone remodeling (TBR) indicates osseointegration, its interpretation remains uncertain. This study aimed to clarify the clinical significance of distinct TBR types-fine TBR (fTBR) and sclerotic TBR (sTBR)-as seen on computed tomography (CT) scans and to evaluate their predictive value for segment stabilization and complete bone fusion and their relationship with interbody cage materials. Methods Seventy-one patients who underwent one-level PLIF with follow-up exceeding 5 years were included. Interbody cages were made of carbon fiber-reinforced polymer (CFRP; 37 segments) or titanium-coated polyether-ether-ketone (TiPEEK; 34 segments). CT images were obtained at 3 months, 1 year, and incidentally at 5 years or later. TBR was classified morphologically as fTBR or sTBR. Results At 1-year postoperatively, the fTBR positivity rate was significantly higher in the TiPEEK group than in the CFRP group (48.6% vs 73.5%, P = .032). The 33 fTBR-positive segments at 3 months had a significantly higher complete fusion rate than 38 fTBR-negative segments (97.0% vs 57.9%, P < .001). There was no significant difference in fusion rates between 27 sTBR-positive segments at 3 months and 44 sTBR-negative segments (66.7% vs 81.8%, P = .15). Conclusions fTBR may serve as a positive indicator for predicting future segment stabilization and bone fusion post-PLIF. sTBR, however, is not associated with future segment stability. This refined TBR classification could enhance postoperative assessment and broaden our understanding of implant-bone integration in spinal fusion.

The segmental innervation patterns of lower extremity muscles remain poorly defined, despite their critical importance in both clinical diagnosis and surgical planning for lumbar spinal conditions. Variability in these patterns, particularly under chronic nerve root compression, complicates the development of accurate diagnostic and therapeutic strategies. This study aimed to elucidate the segmental innervation patterns of lower extremity muscles through intraoperative nerve root stimulation during lumbar spinal surgery combined with motor evoked potential (MEP) during lumbar spinal surgery. A total of 30 patients diagnosed with unilateral nerve root impairment due to degenerative lumbar canal stenosis were enrolled in this study. All patients provided informed consent, demonstrated lower extremity muscle strength graded 4 or higher on the manual muscle test, and were scheduled for surgeries that enabled direct visualization of bilateral nerve roots. During the surgical procedures, 128 lumbosacral nerve roots (L2-S1) were stimulated using a monopolar stimulator, and MEPs were recorded from key lower extremity muscles, including the vastus lateralis, tibialis anterior, and medial gastrocnemius. The vastus lateralis muscle was consistently innervated by the L2 root in 100% of cases, confirming a stable and reproducible pattern. In contrast, stimulation of the L5 root revealed notable anomalies in 8% of cases, where compensatory mechanisms or anatomical anomalies appeared to alter the expected innervation patterns. Furthermore, differences in muscle innervation between the left and right sides were observed in 39% of tested nerve roots, with variability being particularly pronounced in lower lumbar levels, such as L4, L5, and S1.

Purpose: To explore the clinical outcomes associated with screw loosening after S2 alar-iliac (SAI) screw fixation for adult spinal deformity (ASD). Overview of the literature: SAI fixation is widely used in ASD corrective surgery; despite the biomechanical advantages of this screw, complications such as screw loosening remain a significant concern. Methods: We retrospectively reviewed 27 patients undergoing corrective surgery for ASD using SAI as the distal fixation point at a single institution between February 2013 and February 2018. Patients were divided into non-loosening (N) and loosening (L) groups based on radiological evidence of screw loosening (radiolucent area of 1 mm around the screw) and compared for demographic characteristics, bone mineral density (T-score), spinal alignment parameters, and patient-reported outcome using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores. Results: Screw loosening was observed in 78% of patients (n = 21/27); however, there were no statistically significant differences between the N and L groups in terms of the preoperative and 5-year postoperative JOABPEQ scores (p > 0.05 across all domains) and spinal sagittal alignment (p > 0.05). The improvements achieved through corrective surgery were largely maintained regardless of the presence of screw loosening. Conclusions: SAI screw loosening is a common sequela in ASD surgery; however, its loosening might not affect long-term clinical outcomes. Therefore, the choice of fixation should be individualized based on patient factors such as age and bone quality.

Intradiscal condoliase injection therapy (ICIT) is a novel minimally invasive treatment for lumbar disc herniation (LDH). We aimed to compare adverse events, outcomes, and costs of ICIT versus surgery using health claims data. From the database for the period 2020 to 2023, 1,982 ICIT, 4,009 endoscopic discectomy, and 5,528 open discectomy records were extracted. Comparing each surgical group matched to the ICIT group revealed that ICIT had a significantly lower surgical site infection incidence (vs. endoscopic, 0.6% vs. 1.4%, P = 0.016; vs. open, 0.6% vs. 2.8%, P < 0.001), whereas the incidence of additional spine surgery within 90 days was significantly higher (4.9% vs. 2.5%, p < 0.001; 4.9% vs. 1.6%, p < 0.001). The total cost of ICIT group was < 50% of that of discectomy (352,271 vs. 807,550 JPY, P < 0.001; 352,271 vs. 866,642 JPY, P < 0.001). In the first month after treatment, ICIT was associated with the least amount of analgesic prescriptions (76.1% vs. 91.2%, P < 0.001; 76.1% vs. 96.2%, P < 0.001), whereas ICIT was associated with the most in the third month (25.6% vs. 16.0%, P < 0.001; 25.6% vs. 15.7%, P < 0.001). ICIT presents a viable, low-cost treatment alternative to surgery for LDH.

Diffuse idiopathic skeletal hyperostosis (DISH) is a common disease in older adults that causes extensive spinal ankylosis. However, its impact on quality of life (QOL) and locomotive syndrome (LS) remains unknown. Thus, we aimed to evaluate the DISH effect on QOL and LS in community-dwelling middle-aged and older adults. Data of community volunteers who attended a health checkup in 2018-2019 were assessed. A total of 455 subjects were included. Whole spine lateral radiographs were obtained to detect DISH according to the Resnik criteria. QOL was evaluated using SF-36 and EQ5D HUSV. LS was evaluated using the stand-up and two-step tests and GLFS-25. Multivariate regression analysis was performed, adjusting for sex, age, body mass index, and knee osteoarthritis. Additionally, a sex-stratified analysis was performed. DISH was detected in 83 (18.2%) participants. Multivariate analysis demonstrated that DISH was significantly associated with low EQ5D HSUV. Multivariate analysis in men demonstrated that DISH was associated with low PCS, low EQ5D HSUV, high LS stage. Multivariate analysis in women demonstrated that DISH was not associated with any QOL or LS. DISH may be associated with a poor QOL. Additionally, DISH is more common and produces a greater clinical impact in men than in women.

Bone regeneration is a highly demanded but challenging clinical endeavor in orthopedic surgery, necessitating the development of alternative bone grafting materials. This study aimed to evaluate the bone regenerative potential of self-assembling peptide hydrogel (0.8%), bone morphogenetic protein-2 (50 ng/μL), hydroxyapatite, and β-tricalcium phosphate, both individually and in combination with bone chips, in a rat femoral defect model. Ten-week-old female Wistar rats underwent surgical implantation of a polyetheretherketone cage into a 5-mm bony defect within the left femoral mid-shaft, maintained by an external fixator. Polyetheretherketone cages were filled with bone substitute materials alone in the first experiment and with bone substitute materials combined with bone chips in the second experiment. Radiographic and histological analyses were conducted following sacrifice at 56 weeks. While self-assembling peptide hydrogel alone exhibited moderate bone formation, with a bone-volume-to-total-volume ratio of 0.34 ± 0.09, this value was not significantly higher than that of the control group with an empty polyetheretherketone cage. Conversely, the combination of bone morphogenetic protein-2 with bone chips produced the highest level of bone regeneration, with a bone-volume-to-total-volume ratio of 0.78 ± 0.05, significantly surpassing bone chips alone (p < 0.01) and self-assembling peptide hydrogel with bone chips (p < 0.05). These findings suggest that while self-assembling peptide hydrogel holds potential as a scaffold material, particularly in minimally invasive applications, its efficacy in promoting robust bone regeneration may benefit from the inclusion of osteoinductive factors, such as bone morphogenetic protein-2.