Search Results (1,310)

Background and Objectives: Assessing knee extensor (KE) strength is important for detecting muscle weakness in older adults, yet dynamometry is often impractical in community settings. This study examined whether smartphone-derived kinematics during the Five Times Sit-to-Stand Test (FTSST) could predict seated isometric KE strength. Materials and Methods: A cross-sectional study included 105 community-dwelling older adults (68.19 ± 5.85 years). A smartphone application extracted rising time, vertical velocity, and smartphone-estimated relative vertical power during the FTSST. KE strength was measured as maximum voluntary isometric contraction (MVIC) using fixed-frame dynamometry with a Lafayette dynamometer head. Bioelectrical impedance-derived body composition variables were reported descriptively but excluded from the primary prediction models to maintain a transparent movement-based model independent of device-specific body-composition estimates. Hierarchical regression models used smartphone-derived variables and transparent non-BIA covariates. Agreement was examined using Bland–Altman analysis. Results: Smartphone-estimated relative vertical power showed the strongest correlation with MVIC (r = 0.787, p < 0.001). The combined model including sex, age, femur length, and smartphone-estimated relative vertical power explained 71.6% of MVIC variance (adjusted R² = 0.716, SEE = 3.276 kg), outperforming vertical velocity, rising time, and total FTSST time models. Internal validation using repeated 10-fold cross-validation showed CV-R² = 0.701, CV-adjusted R² = 0.689, CV-RMSE = 3.343 kg, and CV-MAE = 2.739 kg. Bland–Altman analysis showed minimal mean bias (0.00 kg), 95% limits of agreement from −6.296 to 6.296 kg, and significant proportional bias (slope = −0.172, p = 0.002), indicating overestimation in weaker individuals and underestimation in stronger individuals. Conclusions: Consistent with our hypothesis, smartphone-estimated relative vertical power was the strongest kinematic predictor of seated isometric KE strength among the evaluated FTSST-derived variables. This approach may support community screening and monitoring, but it should not replace standardized dynamometry for precise individual-level strength quantification. Full article

Background/Objectives: This investigation was performed because corticosteroid injections are commonly used for symptomatic relief in patients with meniscal deficiency, yet their effect on graft survivorship and postoperative outcomes following meniscal allograft transplantation (MAT) remains poorly understood, with limited literature specifically addressing this topic. The aim of this study is to evaluate whether preoperative intra-articular corticosteroid injections (ICS) are associated with reoperation after MAT. Secondary aims included comparing reoperation-free survival, patient-reported outcome measures (PROMs), and patient acceptable symptom state (PASS) achievement. Methods: A retrospective review of 130 adults undergoing meniscal allograft transplantation (MAT) between 2011 and 2023 was performed. Patients with documented corticosteroid injection (CSI) status and ≥2 years of follow-up were included. Exclusion criteria included prior meniscal allograft transplantation, receipt of non-corticosteroid injections (e.g., hyaluronic acid or platelet-rich plasma), concomitant osteotomy procedures, multi-ligament knee reconstruction or inadequate follow-up. Propensity score matching (2:1 no steroid: steroid) based on age, sex, body mass index, fixation technique, operative compartment, and concomitant procedures yielded 54 matched patients (35 no steroid, 19 steroid). The primary outcome was ipsilateral knee reoperation, categorized as major reoperation (revision MAT, anterior cruciate ligament reconstruction, osteochondral allograft transplantation, conversion to total knee arthroplasty, meniscectomy and meniscus repair). Minor reoperations included irrigation and debridement, lysis of adhesions or manipulation under anesthesia, hardware removal, chondroplasty, and synovectomy. Reoperation-free survival was assessed using Kaplan–Meier analysis. PROMs and PASS were compared using adjusted regression models. Statistical significance was set at p < 0.05. Results: Baseline characteristics and follow-up were comparable between groups (7.6 ± 3.5 vs. 6.6 ± 3.2 years; p = 0.30). Overall reoperation occurred in 37.1% of patients in the no-steroid group and 31.6% in the steroid group (p = 0.771). Major reoperation rates were similar (17.1% vs. 15.8%; p = 1.000. There was no significant difference in minor reoperations between groups (20.0% vs. 10.5%; p = 0.468). Kaplan–Meier analysis demonstrated no difference in reoperation-free survival (p = 0.903), with comparable survival at the 1-, 2-, and 5-year time points. No individual subtypes differed significantly between groups. PROMs and PASS achievement were also similar, with no statistically significant differences observed. Conclusions: Preoperative corticosteroid injection was not associated with increased reoperation risk, inferior reoperation-free survival, or worse patient-reported outcomes following meniscal allograft transplantation. However, given the study’s limited power, lack of detailed injection characteristics, and the use of a heterogeneous complication outcome, these findings should be interpreted cautiously, as further investigation is warranted. Full article

Background: The optimal route of tranexamic acid (TXA) administration remains one of the most debated topics in total knee arthroplasty. This study aimed to compare the effects of intravenous (IV), intra-articular (IA), and combined TXA protocols on total blood loss (TBL) and hidden blood loss (HBL), while identifying independent predictors of perioperative bleeding. Methods: In a prospective cohort study of 245 patients undergoing primary TKA, participants were assigned into four groups: IV TXA (15 mg/kg), IA TXA (1 g), combined (IV + IA), and a control group. TBL and HBL were calculated using the Gross formula. A multivariate linear regression model was used to assess independent associations of each protocol. Results: The IV group demonstrated significantly lower TBL (mean 898 mL) and HBL (mean 568 mL) compared with both the control (1329 mL and 894 mL; p = 0.002) and IA groups (1129 mL and 748 mL; p = 0.008). While IA TXA reduced 24 h drain output (p < 0.001), it did not significantly reduce TBL (p = 0.539) or HBL (p = 0.875). No significant differences were found between the IV-only and combined groups (p > 0.05). Multivariate regression identified the IV route as an independent predictor of reduced TBL (B = −383.7, p = 0.001). Conclusion: A single intravenous dose of TXA was associated with lower total and hidden blood loss compared with intra-articular administration. The lack of additional benefit in the combined group suggests a possible plateau effect of systemic administration, which is hypothesis-generating and limited by the study design for blood conservation in TKA. Level of Evidence: Level II, Prospective Cohort Study. Full article

Titanium alloys such as Ti-6Al-4V are widely used in orthopedic implants due to their strength and biocompatibility. Laser Surface Remelting (LSR) offers a promising approach to modify surface properties without altering bulk characteristics. This study investigates the effects of varying melt pool depths (MPDs) from 0 μm to 30 μm in 10 μm steps on the mechanical behavior of Ti-6Al-4V femoral components in Total Knee Replacement (TKR) using a comprehensive computational approach combining Finite Element Analysis (FEA) and computational algorithm-based automated evaluation. A three-dimensional FEA model was developed and tested under four physiological loading conditions: compression, axial distraction, medial bending, and lateral flexion at 1300 N. Results show that increasing MPD from 0 μm to 30 μm increases the maximum von Mises stress by 4.2% under compression but reduces displacement by up to 51.7% under distraction. An MPD of 20 μm reduces displacement by 48% while increasing stress by only 2.7%, representing an optimal balance. The computational algorithm framework identifies 15–25 μm as the optimal range for balancing surface enhancement with mechanical integrity. Experimental validation shows good agreement between simulated and measured results, confirming the reliability of the proposed framework for optimizing surface modification parameters in orthopedic implants. Full article

Background/Objectives: Higher energy and carbohydrate intakes have been hypothesized to enhance resistance training adaptations, yet empirical evidence remains mixed. The purpose of this study was to investigate whether supplemental carbohydrate–energy intake improves muscle hypertrophy and strength. Methods: Twenty resistance-trained men (26.7 ± 4.9 years old, 9.7 ± 6.1 years training experience) completed a quasi-randomized, double-blinded, counterbalanced crossover trial. Participants consumed either a daily protein-only supplement (30 g protein, 4 g carbohydrate) or a daily protein-plus-carbohydrate supplement (30 g protein, 54 g carbohydrate) for 8 weeks each, followed by crossover, while continuing their habitual training and nutrition. Primary outcomes included lean mass obtained using dual-energy X-ray absorptiometry, muscle thickness and cross-sectional area obtained via ultrasound, back squat one-repetition maximum, fatigue index, and knee extensor peak torque. Differences in estimated marginal means, controlling for order and phase effects, were analyzed via linear mixed models, with first-phase-only ANCOVAs as sensitivity analyses. Results: The carbohydrate–protein condition resulted in significantly higher daily energy (+485 kcal/d; p = 0.017) and carbohydrate intake (+33 g/d; p = 0.043) than the protein-only condition, with no differences in protein or fat intake or training volume. No significant differences between conditions were observed for any outcome, including in the sensitivity analyses. Conclusions: Modest supplemental carbohydrate–energy intake did not significantly augment muscle hypertrophy, fatigue resistance or strength in trained men within our study context. More high-powered research is needed to determine how much and under which circumstances carbohydrate–energy intake affects resistance training adaptations. Full article

Background: Egypt is one of the top steel producers in the Middle East and Africa, yet it faces acute water scarcity and rising energy costs, making it a critical context for studying trade-offs among carbon emissions, water ecological effects, and operational cost in steel supply chain. Methods: Using a multi-objective optimization model based on real data from a major Egyptian steel manufacturer, this study evaluates trade-offs among cost, tardiness, and environmental impact measured by carbon emissions and water ecological effects. Unlike prior studies, this study demonstrates that dedicated warehousing enables batch-level traceability of returned scrap while reducing material handling travel time and carbon emissions. The AUGMECON method generates Pareto-optimal solutions, and sensitivity analysis is conducted on six parameters: scrap take-back rate, demand variability, raw material price, energy cost, production capacity, and carbon tax. Results: Demand and raw material prices dominate performance: a 5% demand increase raises cost by 8.6%, and a 15% raw material price increase raises cost by 32.7%. The knee-point solution achieves 58.18 billion EGP, 0.99 months tardiness, and 2096 million kg CO₂ over nine months. Conclusions: This study quantifies the impact of the circular economy and operational parameters on steel supply chain performance under a dedicated warehousing policy. Full article

Background/Objectives: Although vitamin K has been implicated in osteoarthritis pathophysiology, the specific effects of vitamin K2 (menaquinone) on cartilage degeneration remain poorly characterized. This study aimed to investigate the effect of oral vitamin K2 supplementation in a monosodium iodoacetate-induced osteoarthritis model. Methods: Twenty-four male Sprague Dawley rats were included in the study and divided into 3 equal groups: sham group, control (osteoarthritis) group, and treatment group. Saline was applied to the right knee of the sham group, and MIA was applied intra-articularly to the right knee of the control and treatment groups to create an osteoarthritis model. Rats in the treatment group were given 8 micrograms (μg)/day of vitamin K2 orally in addition to the standard diet. After 28 days of follow-up, all rats were euthanized. The right knee articular cartilage was examined histologically with Hematoxylin–Eosin and Safranin O and immunohistochemically with type II collagen alpha 1 and Matrix Metalloproteinase-13. Results: Histological evaluation demonstrated significantly lower Mankin scores in the treatment group (4.25 ± 0.83) compared with the control group (11.10 ± 0.83). Immunohistochemical analysis showed more intense type II collagen staining and reduced matrix metalloproteinase-13 staining in the treatment group relative to the control group. Conclusions: Oral vitamin K2 administration was associated with reduced cartilage degeneration and improved matrix preservation at the 28-day endpoint in an induced MIA osteoarthritis rat model. Full article

Gait analysis is an essential tool in clinical domains for diagnosing musculoskeletal disorders and evaluating rehabilitation, yet traditional marker-based systems are limited by high costs and spatial constraints. To overcome these challenges, this study proposes and evaluates a joint-level hybrid framework that integrates a single RGB camera with two shoe-mounted inertial measurement units (IMUs) to leverage their complementary strengths. The camera-based module estimates hip and knee sagittal joint angles using 3D pose estimation, where the DEAS optimization algorithm aligns estimated coordinates with a humanoid model, and an LSTM-based refinement network corrects hip angles by referencing more accurately estimated knee data. Simultaneously, the IMU-based module estimates sagittal ankle angles through kinematic chain relationships that combine camera-derived proximal joint information with IMU-measured foot orientation. Experimental validation with 11 healthy participants in a controlled laboratory environment demonstrates promising estimation performance, achieving an average mean absolute error (MAE) of 7.89° and RMSE of 10.09° on the held-out test set across sagittal hip, knee, and ankle angles. Leave-one-subject-out (LOSO) cross-validation of the LSTM correction model further confirmed its generalizability, yielding an average MAE of 6.40° across bilateral hip angles. By accurately mitigating the trunk-inclination-induced overestimation of hip angles with a minimal sensor configuration (one camera and two IMUs), the proposed framework provides a practical and interpretable approach for portable lower limb gait analysis. Full article

This paper presents an open-source, fully parametric three-component total knee arthroplasty (TKA) implant system and an automated surgical planning pipeline, addressing the absence of publicly available, modifiable TKA design frameworks in the literature. A cruciate-retaining femoral component, tibial baseplate, and polyethylene insert were designed in Autodesk Fusion with 160 parameters governing all anatomically significant geometry. The femoral articulation surface uses a tangency-constrained triple-radius J-curve. An automated Blender (v. 5.1) Python pipeline performs bone model alignment, size selection from a twelve-size chart, Boolean resection via parametric cutting blocks, and final component placement. Prototypes were 3D printed and validated on 1:1 anatomical bone models. The implant system achieved flush seating on all resection surfaces and impingement-free articulation through the full range of motion on all bone sets. The pipeline correctly aligned bone models, performed resections, and selected appropriately sized implants in all 11 cases, processing each in 1–1.5 min. The system is the first open-source TKA framework to simultaneously provide full parametric definition, documented design rationale, three-component coverage, an automated planning pipeline, and an additive manufacturing fabrication path. By releasing the complete parametric model and pipeline as open source, this work enables independent validation, population-specific adaptation, and iterative improvement by the global research community. Full article

Background/Objectives: Accurate evaluation of knee osteoarthritis (KOA) severity is critical for optimal patient care, yet manual radiographic grading remains subject to observer variability. This study aims to evaluate the performance of a fine-tuned contrastive language–image pre-training (CLIP) framework designed to assist clinicians in grading KOA severity in plain radiographs using the Kellgren–Lawrence (KL) classification system (Grades 0–4). Methods: The model operates by projecting visual features from radiographs and standard textual clinical descriptions into a shared embedding space. Training was conducted using 8260 posterior–anterior (PA) fixed-flexion X-ray images from the Osteoarthritis Initiative (OAI) dataset. For robust external evaluation across distinct data distributions, the model was tested on an independent dataset consisting of 1650 plain radiographs. Results: When evaluated on the external validation dataset, the fine-tuned CLIP model achieved an accuracy of 76.94% and an F1-score of 76.66%. Comparative analysis demonstrates that these aligned vision-language representations provide competitive, stable diagnostic capabilities even when applied to an entirely independent data distribution. Conclusions: Fine-tuned CLIP architectures offer a viable and valuable foundation for semantically transparent, computer-aided evaluation of KOA. Full article

Background/Objectives: Frailty has emerged as a relevant marker of biological vulnerability in patients undergoing complex orthopedic procedures, yet its specific prognostic value in revision total hip and knee arthroplasty remains incompletely synthesized. This systematic review evaluated whether validated preoperative frailty assessment tools are associated with adverse postoperative outcomes after revision total joint arthroplasty and whether available studies allow comparison of prediction performance across instruments. Methods: A systematic search of PubMed/MEDLINE, Embase, the Cochrane Library, Web of Science, Scopus, citation lists, and selected gray-literature sources was performed from inception through January 2026. Gray-literature records and conference abstracts were used only for citation tracking; the synthesis included only full-length peer-reviewed original research articles involving adult patients undergoing revision total hip arthroplasty, revision total knee arthroplasty, or both, with quantitative outcomes according to a validated frailty measure. Because of heterogeneity in frailty tools, outcome definitions, revision indications, and adjustment strategies, findings were synthesized narratively and certainty was assessed by outcome domain. Results: Eleven full-length studies were included, with cohorts ranging from 117 patients to 576,920 admissions, and most were retrospective database analyses. Higher frailty burden was consistently associated with worse short-term outcomes, including complications, prolonged hospital stay, readmission, non-home discharge, resource use, and mortality-related risk stratification. Representative findings included 30-day readmission of 23.8% versus 9.9%, surgical complications of 28.6% versus 7.8%, and odds ratios of up to 10.79 for complications across escalating frailty strata. Prediction studies suggested stronger discrimination for revision-specific or broader models, such as CARDE-B, RAI-rev, and machine-learning approaches, than for simpler generic frailty indices. Conclusions: Frailty is a consistent preoperative marker of elevated short-term perioperative risk after revision arthroplasty. The available evidence supports incorporating frailty assessment into preoperative risk stratification and counseling, but it remains insufficient to establish one universally preferred tool or to prove that frailty screening alone improves outcomes without targeted intervention. Full article

Objective: Serum albumin/creatinine ratio (sACR) integrates nutritional–inflammatory status and renal reserve. We evaluated its ability to predict 1-year reintervention for symptomatic graft occlusion in patients undergoing prosthetic above-knee femoropopliteal bypass for peripheral artery disease (PAD). Methods: This single-center retrospective study included 132 adults (7 women, 125 men) who underwent Dacron above-knee femoropopliteal bypass. The primary analysis evaluated preoperative sACR as a continuous variable. For descriptive comparisons and Kaplan–Meier visualization, patients were stratified according to the median preoperative sACR value (3.77), yielding two groups: <3.77 vs. ≥3.77. The primary endpoint was reintervention for symptomatic graft occlusion confirmed by imaging. Discrimination was assessed using ROC analysis, and the ROC-derived cutoff was interpreted as an exploratory threshold rather than a validated clinical decision point. Associations with 1-year reintervention were assessed using Cox proportional hazards regression analysis (age, diabetes, hypertension, smoking, coronary artery disease, hemodialysis-dependent chronic kidney disease, hemoglobin level, GFR, total protein level, antiplatelet use, and anticoagulant use). Results: Most baseline characteristics were comparable between groups; however, hemodialysis-dependent chronic kidney disease was more frequent in the low-sACR group. Reintervention occurred significantly more often in the low-sACR group from month 1 onward. sACR significantly discriminated 1-year events (AUC = 0.736; p < 0.001). The optimal cutoff was ≤3.7 (sensitivity 90.9%, specificity 64.6%). Higher sACR was associated with lower 1-year event risk in both univariate and multivariate models (adjusted HR 0.61, 95% CI 0.43–0.87; p = 0.007). Conclusions: Preoperative sACR is a practical biomarker associated with early and 1-year reintervention risk after prosthetic above-knee femoropopliteal bypass and may aid perioperative risk stratification. Full article

Background: Tourniquet release during total knee arthroplasty (TKA) can cause abrupt hypotension in elderly patients, but simple intraoperative predictors remain unclear. We evaluated whether blood pressure and the pleth variability index (PVi) predict tourniquet-release hypotension. Methods: In this prospective observational study, 90 elderly patients undergoing TKA with a thigh tourniquet were analyzed. Noninvasive blood pressure and PVi were recorded at predefined perioperative time points. The primary endpoint was hypotension after deflation, defined as mean blood pressure < 65 mmHg. Secondary exploratory endpoints were systolic blood pressure < 90 mmHg and a ≥20% decrease in systolic blood pressure from pre-release values. Results: The primary endpoint occurred in 28.9% of patients and was more common in those with lower pre-release blood pressure. In multivariable analysis, pre-release mean blood pressure and PVi measured immediately after intubation independently predicted hypotension, with odds ratios of 0.95 per 1 mmHg increase and 1.12 per 1-point increase, respectively. The combined model showed moderate discrimination (AUC = 0.71). Similar patterns were observed for systolic definitions, without clear associations with early postoperative complications or hospital length of stay. Conclusions: Lower pre-release mean blood pressure and higher intubation PVi may help identify elderly TKA patients at risk of tourniquet-release hypotension. Full article

Physical energy-based therapies are non-invasive adjunctive interventions that deliver mechanical, electromagnetic, light, or radiofrequency/thermal energy to tissues with the aim of reducing symptoms and improving tolerance of active rehabilitation. Osteoarthritis (OA) is a heterogeneous whole-joint disorder in which cartilage degeneration, subchondral bone remodeling, synovitis, peri-articular tissue dysfunction, neuromuscular impairment, and pain sensitization may interact to produce pain, stiffness, and activity restriction. As conservative therapy for OA, education, progressive therapeutic exercise, weight management when indicated, and self-management remain the core of care. Nevertheless, some patients cannot fully participate in exercise because of pain, fear of movement, load intolerance, comorbidity, or limited access to supervised rehabilitation. This narrative review synthesizes evidence published mainly between 2016 and 2026 for extracorporeal shock wave therapy (ESWT), photobiomodulation/low-level laser therapy (PBMT/LLLT), pulsed electromagnetic field therapy (PEMF), transfer energy capacitive and resistive/capacitive–resistive electric transfer (TECAR/CRET) therapy, body weight support and aquatic unloading strategies, and mechanosonic vibration therapies. The available literature suggests that ESWT and PBMT/LLLT may provide short- to mid-term pain and function benefits in selected patients with knee OA when parameters are aligned with evidence-supported dosing windows. PEMF and vibration therapies show promising but less consistent effects because protocols, devices, sham conditions, and populations vary. TECAR/CRET and unloading approaches are best interpreted as enabling tools that may reduce guarding, improve walking tolerance, or increase the quality of therapeutic exercise, rather than stand-alone disease-modifying treatments. Current national and society guidelines consistently prioritize exercise, education, and weight management; most of the modalities reviewed here are absent from guidelines or are supported only indirectly, which justifies cautious wording and individualized use. A practical application model is, therefore, time-limited and goal-oriented: identify the barrier to rehabilitation, select a modality with a plausible mechanism and published protocol, monitor pain and functional response, and discontinue the modality if it does not improve participation in active care. Full article

This study was based on a 30 m inside-foot long-pass scenario and aimed to preliminarily evaluate the agreement between MediaPipe Pose, DWPose, YOLO-Pose, and Xsens, as well as their practical utility under real-field conditions. Twelve elite male football players performed 15 consecutive long-passes, with data collected simultaneously using Xsens and two smartphones positioned at 15° and 35° to the right front of the participants. The Intraclass Correlation Coefficient (ICC (2,1)) and Bland–Altman analysis were used to evaluate discrete kinematic measures. Continuous kinematic agreement was assessed using Root Mean Square Error (RMSE) and the Coefficient of Multiple Determination (CMD), while Statistical Parametric Mapping (SPM) and Statistical non-Parametric Mapping (SnPM) compared differences across the entire analysis interval. Across the three models, CMD ranged from 0.13 ± 0.17 to 0.67 ± 0.25, and RMSE ranged from 9.88 ± 8.20° to 39.92 ± 10.44°. The SPM and SnPM results showed that significant differences were mainly concentrated in the bilateral hip, knee, and ankle joints. The three models cannot yet be used for field-based high-precision kinematic data measurement; however, MediaPipe Pose and DWPose may be selectively used for rapid screening of movement patterns and analysis of movement trends in football-specific technical movements. Full article