INTRODUCTION:Osteoporotic vertebral fractures (OVFs) are a major cause of morbidity in older adults, leading to pain, disability, and decreased quality of life. Although osteoporosis is traditionally associated with women, men also experience substantial morbidity and mortality after fractures. However, the mechanisms underlying sex differences in OVF remain unclear. This study aimed to investigate sex differences in comorbidities, bone mineral density (BMD), nutritional status, and MRI findings in patients with OVF. METHODS:We retrospectively analyzed 492 patients (126 men and 366 women) hospitalized for OVF between 2015 and 2021. Clinical data, including comorbidities, BMD, Prognostic Nutritional Index (PNI), and MRI signal patterns, were collected. MRI patterns were classified into low- and high-risk groups for delayed bone union. Multivariate logistic regression analysis was performed to identify independent factors associated with high-risk MRI patterns. RESULTS:Men had a significantly higher prevalence of cardiac, renal, and brain disorders, as well as malignancy, compared with women. Men also had significantly higher BMD but lower PNI values. High-risk MRI patterns were more frequent in men in univariate analysis (41.3% vs. 30.0%, p = 0.039). However, multivariate logistic regression analysis revealed that PNI was independently associated with high-risk MRI patterns (OR 0.943 per point increase, 95% CI 0.902-0.986, p = 0.0098), whereas sex was not. CONCLUSIONS:Poor nutritional status was independently associated with high-risk MRI patterns in patients with OVF. The observed sex differences in acute radiological risk may be partially explained or mediated by differences in baseline nutritional status rather than biological sex itself.
BACKGROUND:Coronoid process fractures, which comprise 10-15% of elbow injuries, are critical contributors to joint instability but remain poorly characterised in three dimensions (3D), particularly at the fragment level. This study addressed this gap by generating 3D fracture and heat maps of O'Driscoll Type 1 and Type 2 coronoid fractures to improve the understanding of coronoid process morphology, fracture patterns and inform device designs. METHODS:Thirty-three unilateral CT scans underwent in-silico reduction using Quantitative 3D Computed Tomography (Q3DCT). Fracture lines were overlaid on a healthy coronoid template in anterior, superior, lateral, and medial views to produce detailed maps, and frequency-based heat maps highlighted structural high-fracture points. RESULTS:From the analysed sample, Type 2 fractures predominated (63.6%), with 15 cases of Subtype 2 (oblong anteromedial) and 6 of Subtype 3 (comminuted), while 12 cases were Type 1. Heat maps revealed a single dominant anterior high-density fracture point for Type 1 and Type 2 Subtype 2, multiple superior high fracture-line frequency zones, a mid-height lateral band, and an extended medial path from the trochlear surface to the rim. The analysis shows that these patterns exhibit repetitive fragment shapes: trapezoidal for Type 1, oblong for Subtype 2, and variable for Subtype 3, all of which are crucial for achieving targeted device coverage. CONCLUSION:The findings align with prior mapping studies of O'Driscoll Type 1 and Type 2 fractures; however, they contrast with the reported frequency of anteromedial radial head fractures. Limitations include variable scan quality, exclusion of Type 3 fractures, and a male-dominant, regionally confined cohort. Future work should incorporate Type 3 fractures, broaden demographic diversity, leverage machine-learning segmentation, and perform biomechanical validation to refine patient-specific fixation strategies and generalizability. LEVEL OF EVIDENCE:Level IV: Case Series; Prognosis Study.
BACKGROUND:We compared the associations of height-adjusted appendicular skeletal muscle mass and body mass index-adjusted appendicular skeletal muscle mass with muscle strength, physical performance, and locomotive function-related outcomes in community-dwelling older adults. METHODS:This cross-sectional study included 193 adults aged 65-89 years. Participants were classified into four groups according to low appendicular skeletal muscle mass adjusted for height squared and/or body mass index based on the Asian Working Group for Sarcopenia 2025 criteria. Associations between muscle mass indices and physical performance measures, including grip strength, knee extension strength, gait speed, and two-step test performance, were examined using age- and sex-adjusted linear regression analyses. As EuroQol 5 Dimensions and 25-item Geriatric Locomotive Function Scale scores showed ceiling effects, these outcomes were dichotomized and analyzed using logistic regression. RESULTS:Low muscle mass was identified in 45 participants using height-adjusted appendicular skeletal muscle mass and in 34 using body mass index-adjusted appendicular skeletal muscle mass, with only nine participants meeting both criteria. Participants with low height-adjusted appendicular skeletal muscle mass alone showed lower body mass index and body fat percentage despite preserved physical performance. Conversely, those with low body mass index-adjusted appendicular skeletal muscle mass alone showed higher adiposity and worse physical performance. In adjusted analyses, body mass index-adjusted appendicular skeletal muscle mass was more strongly associated with grip strength, knee extension strength, and two-step test performance, whereas height-adjusted appendicular skeletal muscle mass showed stronger associations with worse EuroQol 5 Dimensions and locomotive dysfunction assessed via the 25-item Geriatric Locomotive Function Scale. CONCLUSIONS:Height-adjusted and body mass index-adjusted appendicular skeletal muscle mass showed different associations with physical performance and locomotive outcomes in older adults. Body mass index-adjusted muscle mass was more closely associated with performance-based physical function, whereas height-adjusted muscle mass was more strongly associated with self-reported health status and locomotive dysfunction.
BACKGROUND:Gravity (1 g) is crucial for musculoskeletal system development and maintenance. Reduced mechanical loading during spaceflight decreases muscle mass and bone mineral density in the lower limbs. However, its effects on the upper limbs remain poorly studied. In this study, we sought to elucidate the impact of lunar gravity on the muscles, bones, and joints of mouse upper limbs. METHODS:Using the Mouse Habitat Unit aboard the International Space Station, male C57BL/6J mice (9-weeks-old) were assigned to either a Ground Control (GC) or a Partial-Gravity (PG) group. PG group mice were exposed to lunar gravity (1/6 g) for approximately 1 month during spaceflight and were euthanized shortly after return to Earth. Upper-limb samples provided by the Japan Aerospace Exploration Agency were used to evaluate the cross-sectional area (CSA) of triceps brachii fibers, cortical bone parameters of the radius and ulna diaphysis, and the thickness of the elbow-joint capsule. RESULTS:Compared with the GC group, the PG group showed no significant differences in cortical bone morphology, but exhibited a trend toward reduced CSA in the triceps brachii and a significant increase in elbow-joint capsule thickness. CONCLUSIONS:In the present study, no marked changes were observed in the muscles or bones of the non-weightbearing upper limbs; however, thickening of the elbow-joint capsule was detected. These findings suggest that exposure to a partial-gravity spaceflight environment is associated with joint capsular thickening; however, whether this effect is directly attributable to gravitational unloading or represents a secondary adaptation to altered activity patterns requires further investigation. These findings may highlight the need for and contribute to the development of strategies for maintaining normal upper-limb function during space missions.
BACKGROUND:The Japanese Pediatric Orthopaedic Association (JPOA) established a nationwide registry for pediatric orthopaedic diseases in 2020. National-level data on late-diagnosed developmental dysplasia of the hip (DDH) and avascular necrosis (AVN) after treatment remain limited. This study aimed to evaluate the frequency of the late diagnosis of DDH, estimate the potential impact of the recommended screening/referral criteria, and identify factors associated with AVN using registry data. METHODS:This retrospective observational study analyzed DDH patients registered between January 2020 and March 2025. A late diagnosis was defined as a diagnosis at ≥12 months of age. Among patients included in the B-registration with complete baseline data, 408 were analyzed for the late diagnosis of DDH. AVN was assessed according to the Salter criteria; 278 patients (305 hips) with available reduction and AVN data were included in the AVN analysis. Multivariable logistic regression was performed to identify independent factors associated with the late diagnosis of DDH and AVN. RESULTS:Late diagnosis occurred in 60 of the 408 patients (14.7%). Referral by an orthopaedic surgeon was independently associated with the late diagnosis of DDH. Among the late-diagnosed patients, 19 (32%) had registry-recorded characteristics that would have met the recommended referral criteria. Under a hypothetical best-case assumption that all 19 patients would have been diagnosed before 12 months of age, the late-diagnosis rate would theoretically have decreased to approximately 10%. AVN occurred in 17 of the 305 hips (5.6%). Relative to Pavlik harness treatment, closed reduction (OR 3.58) and open reduction (OR 11.70) were independently associated with higher odds of AVN. CONCLUSIONS:The late diagnosis of DDH remains prevalent in Japan. Strengthening the implementation of the recommended screening/referral criteria may reduce delayed diagnoses. AVN was independently associated with the reduction method, underscoring the importance of early detection and appropriate treatment selection to minimize complications.
BACKGROUND:Tenosynovial giant cell tumors (TSGCTs) of the fingers have a relatively high recurrence rate. However, no previous studies have examined preoperative magnetic resonance imaging (MRI) data as predictors of recurrence. This study aimed to identify preoperative MRI findings and intraoperative tumor invasion patterns associated with recurrence of TSGCTs of the fingers. METHODS:We retrospectively analyzed 51 patients with TSGCTs of the fingers, who underwent preoperative MRI and surgery. Preoperative MRI parameters included tumor morphology and extent around the phalanx and tendon. Intraoperative findings included Al-Qattan classification and assessment of the neurovascular bundle, bone, joint, and tendon sheath invasion. Preoperative and intraoperative findings were compared between recurrent and non-recurrent groups. RESULTS:Recurrence occurred in six patients (11.8%). The recurrent group showed significantly higher tumor extent around the tendon (82.7 [45.8-100.0] vs. 44.8 [33.4-60.0], p = 0.04), more Al-Qattan Type II cases (66.7% vs. 22.2%, p = 0.04), and more neurovascular bundle invasion (33.3% vs. 2.2%, p = 0.03) than did those of the non-recurrent group. The four recurrent cases without neurovascular bundle invasion exhibited casting mold morphology and tumor infiltration into the deep surface of the tendon. CONCLUSIONS:Tumor extent around the tendon on preoperative MRI was greater in recurrent cases. Casting mold morphology, in cases without neurovascular bundle invasion, may indicate recurrence risk.
BACKGROUND:Early prediction of walking independence after hip fracture surgery can support perioperative decision-making and rehabilitation planning. As functional recovery is dynamic, the predictive value of clinical variables may differ across postoperative phases. This study aimed to develop and internally validate predictive models for postoperative walking independence. METHODS:We conducted a single-center retrospective cohort study of patients aged ≥65 years who underwent surgery for femoral neck or trochanteric fractures at an acute care hospital. Walking independence was defined as a Functional Independence Measure walking item score ≥5 and was assessed at postoperative week 1 (POW1) and postoperative week 4 (POW4). We developed and internally validated prediction models using logistic regression (LR), a nonlinear support vector machine (NLSVM), and a deep neural network (DNN). The data were split into training (80%) and test (20%) sets using stratified sampling. Class imbalance was addressed using simple oversampling in the training set. Model performance was assessed using the area under the receiver operating characteristic curve (AUC) and standard classification metrics. For the DNN, variable contributions were examined using a partial derivative-based method. RESULTS:A total of 368 patients were analyzed. At POW1, all models showed considerable discrimination (AUC, 0.892-0.926), with NLSVM achieving the highest AUC (0.926) and DNN showing the highest sensitivity (0.882). At POW4, LR and NLSVM demonstrated moderate discrimination (AUC, 0.800 and 0.756, respectively), whereas DNN showed comparable discrimination (AUC, 0.778) with the most balanced classification performance. Contribution analysis consistently highlighted positive contributions from early ambulation (within 2 postoperative days) and predominantly negative contributions from older age and longer waiting times to surgery and rehabilitation initiation. CONCLUSIONS:Predictive performance varied according to postoperative phase. The DNN provided the most balanced prediction at POW4 and, together with contribution analysis, may help characterize time-dependent patterns of walking recovery.
BACKGROUND:Proximal humerus fractures (PHFs) are common injuries in older adults. However, the optimal approach to open reduction and internal fixation (ORIF) of PHFs remains a subject of debate. We conducted an updated systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the clinical outcomes between locking plate (LP) and intramedullary nailing (IMN) fixation in ORIF of PHFs with a focus on fracture type. METHODS:We searched PubMed, EMBASE, the Cochrane Library, Scopus, and the ClinicalTrials.gov registry for RCTs published before December 2022. The effects of fixation methods were estimated using odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (95% CI) and a random-effects model. Subgroup analyses were conducted by follow-up period and fracture type. RESULTS:We identified 6 RCTs involving 421 patients. The test of follow-up subgroup differences revealed that IMN fixation tended to yield faster recovery of shoulder joint function than LP fixation. The two approaches did not differ in total complications, but the IMN group had a lower OR for protrusion/cut-out than the LP group in the 2-part (OR: 0.12, 95% CI: 0.01, 0.98) and mixed result reported (OR: 0.28, 95% CI: 0.08, 0.95) subgroups. CONCLUSION:No significant differences in treatment efficacy were observed between the techniques, although IMN showed a lower risk of protrusion/cut-out than LP.
BACKGROUND:Femoroacetabular impingement (FAI) and developmental dysplasia of the hip (DDH) are hip disorders that may be accompanied by sacroiliac joint (SIJ) pain. Although both conditions are considered to alter load transmission across the pelvic ring, differences in SIJ stress patterns between FAI and DDH remain unclear. The purpose of this study was to compare SIJ stress distribution and stress characteristics between FAI and DDH using finite element analysis (FEA). METHODS:This retrospective image-based FEA study included preoperative computed tomography data from 30 hips with FAI and 20 hips with DDH. Three-dimensional models of the pelvis, sacrum, and femur, including SIJ cartilage and surrounding ligaments, were reconstructed. A 90° hip flexion model with a 600 N compressive load applied at L5 was analyzed. The SIJ was divided into superior, middle, and inferior regions, and regional tensile, compressive, and shear stresses were quantified. The direction of stress vectors was assessed qualitatively by visual inspection of vector diagrams to characterize dominant load transmission patterns. RESULTS:In the middle and superior regions of the SIJ, tensile, compressive, and shear stresses were significantly higher in DDH than in FAI (all p < 0.001). In the inferior region, tensile and shear stresses were significantly higher in DDH, whereas compressive stress was significantly higher in FAI (all p < 0.001). Stress vectors were oriented predominantly perpendicular to the SIJ surface in FAI and approximately parallel to the SIJ surface in DDH. CONCLUSIONS:Finite element analysis revealed distinct SIJ stress patterns between FAI and DDH. FAI was characterized by increased compressive stress in the inferior region of the SIJ, whereas DDH showed higher tensile and shear stresses across multiple regions. These findings suggest disease-specific load transmission mechanisms across the pelvic ring and may provide biomechanical insights into SIJ loading associated with different hip pathologies.
BACKGROUND:To evaluate temporal changes in pericruciate fat pad (PFP) edema as a secondary MRI sign of anterior cruciate ligament (ACL) rupture and to determine the diagnostic performance of secondary MRI findings in patients undergoing ACL reconstruction. METHODS:This retrospective study included 188 patients who underwent primary arthroscopic ACL reconstruction with arthroscopically confirmed total ACL rupture. Six secondary MRI findings (anterior tibial translation, ACL-lateral tibial plateau angle, posterior cruciate ligament (PCL) angle, PCL line sign, PCL buckling, and PFP edema) were assessed using predefined criteria. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Intra- and inter-observer reliability were evaluated using intraclass correlation coefficients and Cohen's kappa. ROC analysis assessed the diagnostic performance of PFP edema relative to injury to MRI interval. RESULTS:All secondary findings were significantly associated with ACL rupture (p < 0.001). Overall sensitivity and specificity of PFP edema were 65.4% and 100%, respectively. With a 13-week injury-to-MRI cutoff, sensitivity increased to 85% while specificity and PPV remained 100% (NPV 78%). Other findings showed good diagnostic performance, including anterior tibial translation >5 mm (79.8%/92.5%), ACL-lateral tibial plateau angle <45°(88.8%/91.5%), PCL angle <107° (84.6%/94.5%), PCL line sign (70.2%/91.0%), and PCL buckling (72.3%/86.5%). CONCLUSION:PFP edema is a highly specific and time-dependent secondary MRI sign of ACL rupture, particularly within 13 weeks after injury, and may aid in diagnosis and estimation of injury chronicity when primary findings are inconclusive.
BACKGROUND:In Japan, a nationwide physician work style reform was implemented in April 2024 to regulate overtime hours and improve physicians' working conditions. Orthopedic surgeons represent a high-risk group for occupational burnout due to physically demanding procedures and frequent emergency duties; however, longitudinal evidence on the reform's real-world impact in this population remains limited. METHODS:This longitudinal observational study included 79 full-time orthopedic surgeons affiliated with a university-affiliated hospital network who completed paired surveys in 2023 (pre-reform) and 2024 (post-reform). Outcomes included monthly overtime hours, health-related quality of life assessed by the EuroQol 5-Dimension (EQ-5D-5L) and 36-Item Short Form Health Survey (SF-36), and psychological well-being assessed by the Hospital Anxiety and Depression Scale (HADS). Statistical comparisons were performed using the Wilcoxon signed-rank test and McNemar test for paired categorical variables. RESULTS:Monthly overtime hours showed a non-significant reduction from 49.2 ± 23.6 to 46.0 ± 22.1 h (P = 0.191), and the proportion working ≥80 overtime hours per month decreased from 10.1% to 7.6% (P = 0.774, McNemar test). HADS anxiety and depression scores did not change significantly. In contrast, EQ-5D scores improved significantly from 0.86 ± 0.10 to 0.89 ± 0.10 (P = 0.009). Among SF-36 subscales, role physical demonstrated a trend toward improvement (P = 0.054). CONCLUSIONS:The physician work style reform period was associated with a modest but statistically significant improvement in health-related QOL among orthopedic surgeons; however, given the absence of a control group, causal attribution to the reform itself cannot be established. It is noteworthy that the median EQ-5D score was unchanged, and the mean improvement was primarily driven by a reduction in low-scoring outliers, suggesting that the benefit was concentrated among physicians with the greatest baseline impairment. These findings suggest that regulation of working hours alone is insufficient to substantially improve physician well-being, and that broader organizational interventions are warranted.
BACKGROUND:Acetaminophen is widely used in multimodal analgesia after total joint arthroplasty (TJA), but the comparative effects of different regimens remain uncertain. METHODS:PubMed, Embase, Cochrane Library, and Web of Science were searched through September 22, 2025 for randomized controlled trials evaluating acetaminophen or propacetamol regimens after total hip or knee arthroplasty. A Bayesian network meta-analysis was performed using R 4.4.0 and JAGS 4.3.1. Outcomes included pain scores at 6, 12, and 24 h and 24 h supplemental analgesic consumption, expressed as standardized mean differences (SMDs) with 95% credible intervals (CrIs). RESULTS:Fifteen RCTs including 1986 patients and six interventions were analyzed. For 24 h supplemental analgesic consumption, multiple-dose intravenous propacetamol and multiple-dose intravenous acetaminophen ranked highest (SUCRA 90.37% and 86.94%) and were superior to control (SMD 0.49 [0.18, 0.81] and 0.45 [0.27, 0.63], respectively). For 24 h pain, multiple oral and multiple intravenous acetaminophen reduced scores versus control (SMD 0.25 [0.05, 0.45] and 0.18 [0.005, 0.35], respectively). No significant differences were found at 12 h. At 6 h, multiple-dose intravenous propacetamol showed the largest effect (SMD 0.96 [0.49, 1.42]). CONCLUSIONS:Acetaminophen-based regimens may provide modest postoperative analgesic and opioid-sparing benefits after TJA, particularly with selected multiple-dose intravenous protocols. However, no single regimen was consistently superior across outcomes and time points, and SUCRA rankings should be interpreted alongside effect estimates and clinical feasibility.
BACKGROUND:Achieving tension-free repair of large and massive rotator cuff tears remains challenging. Although muscle advancement techniques have been proposed, their biomechanical effects remain unclear. This study evaluated the effects of stepwise supraspinatus (SSP) and infraspinatus (ISP) muscle advancement on tendon-footprint distance in a porcine ex vivo model. METHODS:Twelve shoulders from seven porcine specimens were prepared by detaching the SSP and ISP tendons from the footprint, followed by a standardized resection of 15 mm of the tendon stump. The tendon-footprint distance was measured under a 20 N load. Four conditions were tested: control, SSP alone, SSP + upper ISP, and SSP + entire ISP. Data were analyzed using the Friedman test with post hoc Wilcoxon signed-rank tests and Bonferroni correction. RESULTS:The median (interquartile range) distances were 23.0 (18.8-26.3) mm in the control, 19.0 (15.0-24.0) mm with SSP alone, 16.5 (9.8-18.3) mm with SSP + upper ISP, and 0.5 (0.0-4.0) mm with SSP + entire ISP. Significant differences were observed among conditions (P < 0.001). SSP + entire ISP showed significantly smaller distances than all other conditions (P = 0.015). SSP + upper ISP also showed smaller distances than control (P = 0.032) and SSP alone (P = 0.036), whereas no difference was found between control and SSP alone (P = 0.132). CONCLUSIONS:Stepwise muscle advancement progressively reduces the tendon-footprint distance, with SSP+entire ISP providing the greatest effect. ISP advancement may be critical for tension-free repair.
BACKGROUND:Thoracic ossification of the ligamentum flavum may cause severe myelopathy. Vascular angiogenesis in normally avascular ligament tissues is central to its pathogenesis; however, the mechanisms remain unclear. Additionally, although DNA methylation is a well-known epigenetic mechanism, its role in ligament ossification has not been previously defined. METHODS:We investigated the potential involvement of epigenetics and angiogenic factors in the development of thoracic ossification of the ligamentum flavum. Samples were collected from 35 patients with thoracic ossification of the ligamentum flavum who underwent spinal surgery and 12 patients with lumbar spinal canal stenosis or disc herniation without this condition. Tissue sections were used for histological and immunohistochemical studies, whereas primary ligamentum flavum cells were analyzed for DNA methylation and immunoblotting. Bisulfite sequencing was used to analyze DNA methylation and associated pathways. RESULTS:DNA methylation analysis identified vascular endothelial growth factor, fibroblast growth factor, and epithelial adherens junction signaling pathways as being significantly associated with angiogenesis. Vascular-related probes with high methylation rates included vascular endothelial growth factor, cluster of differentiation 34, secreted frizzled-related protein 1, and SRY-box transcription factor 17. These genes were highly expressed in the affected tissues. Immunohistochemistry revealed the presence of vascular endothelial growth factor and cluster of differentiation 34 in mature and hypertrophic chondrocytes at the ossification front, secreted frizzled-related protein 1 and SRY-box transcription factor 17 in mesenchymal cells surrounding the ossification front, and fibroblasts in degenerated ligament regions. Taken together, these findings suggest that neovascular proliferation occurs as a result of ligament degeneration, and that DNA methylation may influence whether these newly formed vessels acquire ossification-promoting properties. CONCLUSIONS:DNA methylation changes may be associated with the expression of factors related to ossification. Pathway analysis identified angiogenesis-related signals as significant, highlighting the importance of neovascularization in the process of ossification.
BACKGROUND:Japan is one of the most rapidly aging countries in the world, making long-term monitoring of hip fracture trends crucial for health policy. This study aimed to analyze changes in the epidemiology and treatment patterns of hip fractures using nationwide survey data from 1998 to 2023. METHODS:Annual surveys were conducted from 1998 to 2023, targeting Japanese Orthopaedic Association-certified training facilities and clinics with inpatient facilities affiliated with the Japanese Clinical Orthopaedic Association. We registered femoral neck and trochanteric fractures in patients aged ≥35 years and collected data on age, sex, fracture type, injury circumstances, treatment methods, hospital stay duration, and age-adjusted incidence rates. RESULTS:The total number of cases increased 3.5-fold, from 35,333 in 1998 to 122,940 in 2023. The mean age rose from 78.7 to 83.3 years, with cases aged ≥90 years showing a 37-fold increase. Age-adjusted incidence rates in women peaked around 2015, declined by 2020, and recently plateaued. In men, marked increases were observed from 2005 to 2015, particularly in those aged ≥80 years, with high levels continuing through 2020-2023, showing age-class-specific stability or slight variations. The femoral neck/trochanteric fracture ratio reversed from 0.78 to 1.10, and femoral neck fractures became predominant after 2020. The operative treatment rate was 94.7% in 2023, with a mean preoperative waiting time of 4.0 days. Indoor injury rates increased from 63.6% to 77.2%, whereas hospital stays decreased by 36.1% from 54.8 to 35.0 days. CONCLUSIONS:This 26-year continuous survey revealed a marked increase in hip fractures, particularly in the super-elderly population. While healthcare efficiency has improved, further enhancements are necessary to address anticipated future increases. Hip fracture incidence appears to plateau in women while remaining relatively high in men, indicating the need to strengthen primary and secondary prevention strategies for male osteoporosis.
BACKGROUND:Stress fractures at the base of the second metatarsal are characteristic overuse injuries in ballet dancers, caused by repetitive forefoot loading during pointe work. Conservative treatment may sometimes result in delayed healing or recurrence in a subset of patients. METHODS:We retrospectively reviewed five female ballet dancers with second metatarsal base stress fractures unresponsive to at least 3 months of conservative care, defined as persistent pain with no CT evidence of bone union despite activity restriction and off-loading. All underwent fixation with two Headless Cannulated Screw (HCS) via a dorsal mini-open approach, without immobilization. Outcomes included radiographic union confirmed by CT, time to resumption of pointe work, jumps, and return to preinjury activity level, as well as functional recovery assessed with the JSSF midfoot scale. CT-based union was independently assessed by two observers. RESULTS:All dancers achieved radiographic union within 11 weeks (mean, 7.0 ± 3.4 weeks; median, 6; IQR, 5-10). There was complete agreement between observers (100% agreement; ICC, 1.0 [95% CI, 1.0-1.0]). FWB occurred at a mean of 4.4 ± 3.0 weeks (median, 3; IQR, 3-6). Pointe work resumed at a mean of 7.4 ± 3.2 weeks (median, 6; IQR, 6-8), and jumping at 8.8 ± 3.3 weeks (median, 8; IQR, 7-9). Return to preinjury activity level occurred at a mean of 13.8 ± 5.0 weeks (median, 12; IQR, 10-17). The mean JSSF midfoot score improved from 77.8 ± 5.4 preoperatively to 98.0 ± 4.5 postoperatively. No recurrences or implant failures were observed at a mean 5-year follow-up. One patient experienced transient postoperative foot numbness that resolved within 3 months. CONCLUSIONS:These preliminary observations suggest that this technique may be considered a potential option requiring further comparative evaluation for selected patients at risk of delayed union or recurrence. However, spontaneous progression toward union cannot be excluded, and treatment efficacy cannot be established without a comparison group. LEVELS OF EVIDENCE:Level Ⅳ, Case series.
BACKGROUND:Longitudinal studies investigating the relationship between oxidative stress and sarcopenia remain limited. In this study, we aimed to investigate whether oxidative stress, measured using the derivatives of reactive oxygen metabolites (d-ROMs) test, could independently predict progression to sarcopenia in community-dwelling older adults and determine clinically relevant cutoff values for risk stratification. METHODS:This longitudinal cohort analysis included 200 participants aged ≥60 years followed-up for of >5 years. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Participants were classified into a preserved group and declined group (those who developed sarcopenia or presarcopenia during follow-up). Between-group comparisons were conducted, and multivariate logistic regression analysis was performed to identify independent risk factors for sarcopenia progression. Receiver operating characteristic (ROC) curve analysis was applied to determine the optimal cutoff values of oxidative stress markers. RESULTS:Over a mean follow-up of 5.9 years, 51 participants (25.5%) progressed to sarcopenia or presarcopenia. The declined group was significantly older than the preserved group (68.9 vs. 67.1 years; P = 0.029) and demonstrated significantly higher baseline d-ROM levels (357.6 vs. 315.9 U.CARR; P = 0.005), while other blood biomarkers showed no significant differences. Multivariate logistic regression analysis identified elevated d-ROMs as an independent risk factor for sarcopenia progression, with a 2.33-fold increased risk per 50 U.CARR increase (95% confidence interval, 1.37-4.27; P = 0.003). ROC analysis revealed that a d-ROMs cutoff value of 335.0 U.CARR best predicted progression, with an area under the curve of 0.691. CONCLUSIONS:Elevated oxidative stress was independently associated with progression to sarcopenia in community-dwelling older adults, suggesting that oxidative stress assessment using d-ROMs may help identify individuals at increased risk and support strategies aimed at reducing reactive oxygen species burden as a potential approach for sarcopenia prevention and future research.
BACKGROUND:Cervical segmental rotation has rarely been quantified in physiological upright, weight-bearing positions. This study aimed to characterize cervical rotational kinematics using upright multidetector CT (MDCT) and to evaluate the independent associations between rotational parameters, age, sex, and cervical sagittal alignment. METHODS:Forty-nine healthy volunteers-24 younger (21-40 years) and 25 elderly (61-79 years)-underwent upright MDCT in an upright standing position and maximal right cervical rotation. Rotational angles (O-C7) were measured relative to T1. Parameters included segmental rotational range of motion (ROM) (rsd: intervertebral rotation change from neutral to maximal rotation), rotated segmental position (rd: intervertebral rotation at maximal rotation), and percentage segmental contribution (%rsd). RESULTS:The largest segmental ROM occurred at C1-2 (median rsdC1: 34.3°), accounting for 66.1% of total rotation. Compared with younger participants, the elderly group showed significantly reduced total rotation and rsdC1 (30.3° vs. 37.0°, p = 0.008). Correlation analysis showed that age correlated negatively with rsdC1 (r = -0.31) and positively with rsdC7 (r = 0.29). Multivariable regression identified elderly age as a significant negative predictor of rsdC1 (β = -5.59, p = 0.004). In contrast, rdC1 was independently associated with age (β = -6.05, p < 0.001), male sex (β = -5.30, p = 0.003), and smaller C2-7 angle (β = -0.14, p = 0.020). CONCLUSIONS:Under physiological weight-bearing conditions, cervical rotation is predominantly generated at C1-2. Aging reduces upper cervical segmental ROM, potentially leading to compensatory motion at the cervicothoracic junction. While rotational ROM is primarily dictated by age, the intervertebral position at maximal rotation is independently influenced by age, sex, and sagittal alignment. These normative data may serve as a reference for future studies examining cervical disorders and postoperative rotational function.
