Search Results (138)

Arthrogenic muscle inhibition (AMI), neurophysiological suppression of voluntary quadriceps activation triggered by joint effusion and inflammation, is consistently initiated within hours of any form of knee surgery. If not actively counteracted during the first two postoperative weeks, AMI may drive a cascade of neuromuscular, morphological, and biomechanical deficits that can persist for years, substantially increasing the risk of post-traumatic osteoarthritis, reinjury, and long-term functional disability. Emerging evidence indicates that preoperative patient-related factors, including baseline quadriceps strength, age, body mass index, and physical fitness, further modulate the rehabilitation response and should be considered in planning early postoperative protocols. This narrative review, which was not designed as a systematic review or meta-analysis and therefore does not include formal quality assessment or pooled statistical analysis, evaluates evidence for seven early-phase (0–2 weeks postoperative) knee muscle activation interventions: neuromuscular electrical stimulation (NMES), isometric quadriceps exercise, blood flow restriction (BFR) training, electromyographic (EMG) biofeedback, open and closed kinetic chain (OKC/CKC) exercise, cryotherapy, and continuous passive motion (CPM). Findings are synthesized against six clinically relevant dimensions, safety in the 0–2 week window, home-based usability, capacity to overcome AMI, requirement for volitional effort, objective monitoring capability, and progressive resistance, to characterize a consistent pattern: no single existing modality simultaneously meets all combined requirements for home deployment, volitional engagement, objective monitoring, and progressive resistance from postoperative day one. This collective unmet need provides direction for future device development and clinical research. Full article

Objective: Femoral head fractures are rare and severe injuries often associated with high-energy trauma. Early recognition and rapid, stable reduction are essential for successful treatment to prevent complications and morbidity. This retrospective study aims to describe and analyze long-term outcomes and survival rates of the femoral head after a Pipkin fracture. Methods: Between 2012 and 2021, all patients with a femoral head fracture who were treated in a Level I Trauma Center were assessed and analyzed. Two examiners performed a physical examination and radiological control of patients and called the patients for a final follow-up. Anterior and posterior fracture-dislocations and femoral head fractures were classified according to Pipkin’s classification system. The functional outcome was assessed using the Harris Hip Score (HHS). Results: Over a 10-year period, n = 15 patients were diagnosed with a femoral head fracture. All patients were male; the average age at admission was 41.3 years. The mean follow-up was 43.7 months ± 46 months. No complications occurred in three patients (20%). Twelve patients had complications. The most common complications were nerve lesions and posttraumatic osteoarthritis. Regarding the outcome, no data were available for two patients; one patient died, and two of four patients remained with a Girdlestone resection arthroplasty at the follow-up. The mean score in HHS was 76.69 ± 20.3 (mean ± standard deviation). Conclusions: An overall complication rate of 80% was observed; however, functional outcomes were generally moderate at final follow-up. These findings highlight the considerable risk of complications associated with femoral head fractures, particularly nerve injury and posttraumatic osteoarthritis. Notably, six of 15 patients no longer retained their native hip joint at the time of assessment. The study is a Level 2b study. Full article

Post-traumatic osteoarthritis (PTOA) is a rapidly progressing joint disorder initiated by acute injury, characterized by persistent inflammation, chondrocyte dysfunction, and extracellular matrix (ECM) degradation. Despite its clinical burden, effective disease-modifying therapies are lacking. Increasing evidence suggests that the ubiquitin–proteasome system, particularly E3 ubiquitin ligases, plays a pivotal role in regulating key pathogenic pathways involved in PTOA and represents a potentially druggable regulatory axis. In this review, we provide a comprehensive overview of the emerging roles of E3 ubiquitin ligases in PTOA, highlighting their involvement in inflammatory signaling, chondrocyte fate regulation, and cartilage matrix remodeling. We further integrate the current findings into a unified framework, in which E3 ligases act as central regulatory nodes linking injury-induced molecular responses to chronic joint degeneration. Importantly, we emphasize the pharmacological and translational potential of targeting E3 ubiquitin ligases as a novel therapeutic strategy. Recent advances in small-molecule modulators, gene-based interventions, and proteolysis-targeting chimeras (PROTACs) highlight the druggability of this regulatory system and provide new opportunities for disease-modifying treatment in PTOA. We also discuss the current challenges, including context-dependent effects, limited PTOA-specific validation, and delivery barriers. Overall, this review provides a comprehensive and therapeutically oriented perspective on E3 ubiquitin ligases in PTOA and highlights their potential as promising targets for pharmacological intervention and disease-modifying therapy. Full article

This study aimed to evaluate the therapeutic effects of platelet-rich plasma (PRP) and Cervus and Cucumis polypeptide (CCP) injections in rats with post-traumatic osteoarthritis (OA). The model was established by transection of the anterior cruciate ligament, and the animals were subsequently treated with PRP and CCP. Articular cartilage degeneration was assessed through gross morphological observation, histopathological staining, and a standardized scoring system. Concurrently, pain-related behaviors, joint swelling, levels of inflammatory cytokines, and markers associated with extracellular matrix degradation were measured. The results demonstrated that, compared with the OA model group, PRP and CCP exhibited varying degrees of functional improvement, specifically, a reduction in pain-related behaviors and an alleviation of joint swelling. Furthermore, cartilage morphological damage was diminished, inflammatory marker levels decreased, and indicators of extracellular matrix degradation were attenuated. Histopathological examination of liver and kidney tissues revealed no apparent abnormalities. This study provides valuable experimental evidence for further treatment strategies for OA. Full article

The rising popularity of sports practiced without adequate preparation has increased the incidence of anterior cruciate ligament (ACL) injuries, particularly among young individuals. Because the ACL has a very limited intrinsic healing capacity, surgical reconstruction—most often using autologous grafts—remains the standard of care. However, current techniques frequently lead to donor-site morbidity and do not consistently restore long-term joint stability, contributing to early post-traumatic osteoarthritis in active patients. Over the past decades, tissue engineering (TE) has opened promising avenues for developing biological substitutes capable of overcoming these limitations. Despite substantial progress, no strategy has yet demonstrated reliable and clinically validated functional regeneration of the human ACL. Meanwhile, artificial intelligence is emerging as a complementary tool for diagnosis, surgical planning, biomechanical assessment, and personalized reconstruction strategies. This review aims to provide a comprehensive overview of current TE-based approaches for ACL repair and reconstruction, analyzes their biological and biomechanical limitations, and discusses emerging concepts that may enhance future clinical outcomes. We first summarize the fundamental principles of tissue engineering, then examine the major strategies proposed for ACL regeneration—highlighting their respective strengths and shortcomings—and finally outline perspectives for a novel approach currently under development. Full article

Background: Post-traumatic osteoarthritis (PTOA) lacks effective disease-modifying therapies that preserve joint structure while promoting tissue repair. This study aimed to evaluate the therapeutic efficacy and underlying mechanism of Biluo Qianyuan Formula (BLQYF), a standardized herbal formulation derived from clinical practice, as a potential disease-modifying alternative to celecoxib in a murine model of PTOA. Methods: A murine PTOA model was established and treated with BLQYF at different doses, with celecoxib serving as a pharmacological comparator. Safety was assessed by hepatic and renal toxicity analyses. Therapeutic effects were evaluated using micro-computed tomography (micro-CT) and histological staining. Network-based integrative analyses were conducted to identify key regulatory targets, followed by experimental validation in fibroblast-like synoviocytes. Results: BLQYF was well tolerated under the experimental conditions, with no detectable hepatic or renal toxicity at therapeutic doses. Micro-CT and histological analyses demonstrated that BLQYF dose-dependently mitigated subchondral bone deterioration, enhanced cartilage regeneration, and restored collagen deposition. At higher doses, BLQYF showed therapeutic efficacy comparable to celecoxib, with superior outcomes regarding cartilage reparation. Mechanistically, integrative analyses identified fibronectin 1 (FN1) as a central regulatory hub. Validation experiments confirmed that BLQYF suppressed FN1, MMP3, and TGF-β expression in fibroblast-like synoviocytes, thereby attenuating inflammation and extracellular matrix degradation. Conclusions: These findings support BLQYF as a promising disease-modifying therapeutic candidate for PTOA and highlight the fibroblast–FN1 axis as a novel pharmacological target for intervention. Full article

Background: Knee arthrodesis markedly alters lower limb biomechanics and creates a challenging scenario when associated with end-stage ankle osteoarthritis. No prior reports have specifically described treatment with total ankle replacement (TAR) in the presence of an ipsilateral fused knee. This study evaluated the feasibility and mid-term outcomes of TAR in this rare condition. Methods: Two patients with post-traumatic end-stage ankle osteoarthritis and long-standing knee arthrodesis underwent TAR using a lateral transfibular approach with a Zimmer Trabecular Metal™ implant. Surgical planning aimed to restore coronal and sagittal alignment. Postoperative management and rehabilitation were specifically adapted to the absence of knee motion, with emphasis on gait re-education. Clinical and radiographic follow-up was performed up to 36 months. Results: At final follow-up, both patients showed substantial pain reduction, improved ankle range of motion, and recovery of a stable, functional gait compatible with knee fusion. Imaging demonstrated well-aligned, stable components without loosening or subsidence. No major complications or reoperations occurred. Conclusions: Lateral transfibular TAR appears feasible and effective for end-stage ankle osteoarthritis in patients with ipsilateral knee arthrodesis, preserving ankle motion and supporting functional ambulation in this complex setting. Full article

Background: Focal chondral and osteochondral knee defects have limited intrinsic healing capacity and may progress toward post-traumatic osteoarthritis. Early post-operative inflammatory signaling may influence clinical recovery after cartilage repair. This prospective, single-center observational cohort study aimed to characterize short-term post-operative inflammatory biomarker profiles in synovial fluid and serum after AMIC and to assess associations with patient-reported outcomes over 12 months. Methods: Fifteen patients undergoing autologous matrix-induced chondrogenesis (AMIC) for focal knee chondral/osteochondral defects were prospectively enrolled. International Knee Documentation Committee (IKDC) and Lysholm scores were recorded pre-operatively and at 6 and 12 months. Synovial fluid and serum were collected intraoperatively, at 6 and 12 weeks post-operatively. Interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), and IL-6 were quantified using multiplex flow luminescence immunoassay, and the total synovial fluid protein level was measured. Non-parametric repeated-measures testing and Spearman’s rank correlation were applied (p < 0.05). Results: IKDC and Lysholm scores improved from (30.6 ± 9.4) to (58.8 ± 15.0) and from (57.5 ± 18.6) to (78.2 ± 14.7), respectively, exceeding established minimal clinically important difference (MCID) thresholds. Synovial fluid IL-1β and IL-1RA increased significantly over time ((p = 0.01357) and (p = 0.03953), respectively); IL-1β remained elevated, whereas IL-1RA tended to decline after 6 weeks. IL-6 levels remained low throughout. Total synovial fluid protein increased significantly (p = 0.00043). No significant correlations were observed between corresponding biomarker levels in synovial fluid and serum. Higher IL-6 and a higher IL-1β/IL-1RA ratio were associated with poorer clinical improvement (ρ = −0.80, p < 0.05 and ρ = −0.580, p < 0.05, respectively). Conclusions: AMIC was associated with a sustained intra-articular inflammatory response despite favorable 12-month outcomes. Exploratory analyses suggest that inflammatory dysregulation—particularly involving IL-6 and IL-1β/IL-1RA balance—may be linked to less favourable clinical recovery. Synovial fluid measurements provided more relevant information on local joint biology than serum sampling. Full article

Background: Distal tibial fractures (DTFs) are a major cause of post-traumatic osteoarthritis (PTOA). The risk of conversion to total ankle arthroplasty (TAA) or ankle fusion (AF) after DTFs remains unclear, and the current literature provides heterogeneous and often incomplete data. The aim of this systematic review was to evaluate the incidence of TAA and AF following DTF-related PTOA and to explore potential predictors of conversion, including initial treatment strategy. Methods: A systematic review was conducted according to PRISMA guidelines. The PICO framework was applied during the study design and literature search phase to define the research question and eligibility criteria. Studies reporting adult patients with a history of DTFs who later developed PTOA and underwent TAA or AF were included. Descriptive statistics were performed. Study-level proportions of conversion to TAA, AF, or both were analyzed using random-effects meta-analysis with logit transformation. Results: Eight studies comprising 190,383 fractures met the inclusion criteria. Overall, 31,269 patients underwent TAA or AF, corresponding to a conversion rate of 16.4%. The pooled conversion incidence from the random-effects model was 5.6%, with considerable heterogeneity (I² ≈ 100%). When procedures were analyzed separately, the pooled incidence was 0.25% for TAA and 0.76% for AF. Conclusions: The risk of conversion to TAA or AF after DTFs appears to be relatively low, despite the high prevalence of PTOA. The higher conversion rate observed in surgically treated fractures likely reflects the complexity of the initial fracture rather than the failure of surgical management itself. Level IV, systematic review of retrospective studies. Full article

Background and Objectives: Acetabular fractures in elderly patients are increasing in incidence and are frequently associated with osteoporotic bone, fracture comminution, marginal impaction, and pre-existing joint degeneration. Open reduction and internal fixation (ORIF) alone in this population is associated with high rates of fixation failure, post-traumatic osteoarthritis, and secondary conversion to total hip arthroplasty (THA). Acute THA, with or without concomitant internal fixation, has emerged as an alternative strategy aimed at enabling early mobilization and reducing reoperation rates. Materials and Methods: We retrospectively reviewed a series of elderly patients who sustained an acetabular fracture and were treated with acute THA, either as a standalone procedure or combined with internal fixation. Demographic data, fracture patterns, surgical technique, implant choice, complications, and short-term clinical and radiographic outcomes were analyzed. Results: Acute THA allowed immediate or early weight bearing in all patients. Implant stability was achieved using a highly porous, multi-hole acetabular component with supplemental screw fixation and selective use of internal fixation to restore columnar stability when required. Complications were comparable to those reported in the contemporary literature for acute THA in acetabular fractures. Conclusions: In carefully selected elderly patients with acetabular fractures at high risk of failure after ORIF, acute THA with or without internal fixation represents a viable definitive treatment strategy, enabling early mobilization and avoiding the morbidity associated with delayed salvage arthroplasty. Full article

Imaging is the gold standard for diagnosing osteoarthritis (OA). However, it remains challenging to precisely assess OA in murine models. The aim of this study is to establish μCT-based geometric indices for assessing the disease severity of post-traumatic OA (PTOA) and age-related OA (AROA). Following medial meniscectomy (MMS) in adult C57BL/6 mice, distal femoral length remained unchanged, whereas its width increased significantly. As a result, distal femoral width-to-length ratio was markedly elevated at 4 and 8 weeks after MMS (1.33 ± 0.05 and 1.47 ± 0.1, n = 7 and 5 joints, respectively) compared to contralateral normal joints (1.19 ± 0.04, n = 9), yielding an area under the curve (AUC) of 1.0 (95% CI, 1.0–1.0). Similarly, the tibial secondary ossification center (IIOC) height decreased, whereas its width increased after MMS. Consequently, the tibial IIOC height-to-width ratio was significantly reduced at 4 and 8 weeks post-MMS (0.25 ± 0.02 and 0.24 ± 0.02, respectively) compared with a normal joint (0.304 ± 0.011), with an AUC of 1.0 (95% CI, 1.0–1.0). Bland–Altman analysis demonstrated strong interrater reproducibility, with intraclass correlation coefficients of 0.853 (95% CI, 0.681–0.936) for the femoral ratio and 0.887 (95% CI, 0.748–0.952) for the tibial ratio. Notably, these MMS-induced changes in femoral and tibial geometric indices were attenuated in mice with genetic deletion of GM-CSF, a key mediator of OA. Importantly, μCT-derived geometric indices were validated by histological analysis. Furthermore, increased distal femoral width-to-length ratio and reduced tibial IIOC height-to-width ratio were also observed in the knee joints of 28-month-old mice with AROA. In addition, an enlarged patella and a calcified synovium–capsule serve as a reference for AROA and PTOA. Collectively, μCT-based geometric indices are useful and easily quantifiable metrics for assessing disease severity and therapeutic response of PTOA and AROA models in murine. Of note is that the distal femoral and proximal tibial geometric indices were developed based on severe OA induced by MMS, and their applicability to mild OA requires further investigation. Full article

Anterior Cruciate Ligament (ACL) injuries are among the most common knee injuries sustained during sport. Following injury, only 65% of patients may return to their previous level of sport. Individuals who have suffered ACL injury are far more likely to develop post-traumatic osteoarthritis of the knee (PTOA). This suggests an unmet need for strategies to help advance return to play, reduce risk of PTOA, and provide additional options for pain management after ACL injury. Extracorporeal shockwave therapy (ESWT) and radial pressure waves (RPW) are non-invasive treatment options that have been shown effective for treatment of a variety of orthopedic injuries. This perspective proposes the use of ESWT and RPW as treatment options during the peri-operative and post-operative management of ACL injuries, with the goal of modifying risk for PTOA. The available literature indicates that ESWT may have chondroprotective effects after ACL injury, and numerous clinical trials demonstrate the effectiveness of ESWT and RPW for orthopedic conditions including tendinopathy or bone marrow edema. Limited data and a lack of consensus on standardized rehabilitation protocols present gaps in the literature and emphasize the need for research leading to evidence-based recommendations for the use of ESWT and RPW to modify risk for the onset of PTOA after ACL injuries. Full article

Meniscal preservation is increasingly recognized as a critical determinant of long-term knee joint health, yet successful repair remains challenging due to the meniscus’s limited intrinsic healing capacity. The adult meniscus is characterized by restricted vascularity, low cellularity, a dense extracellular matrix, complex biomechanical loading, and a hostile post-injury intra-articular inflammatory environment—factors that collectively impair meniscus healing, particularly in the avascular zones. Over the past several decades, a wide range of biologic augmentation strategies have been explored to overcome these barriers, including synovial abrasion, fibrin clot implantation, marrow stimulation, platelet-derived biologics, cell-based therapies, scaffold coverage, and emerging biologic and biophysical interventions. This review summarizes the biological basis of meniscal healing, critically evaluates current and emerging biologic augmentation techniques, and integrates these approaches within a unified framework of vascular, cellular, matrix, biomechanical, and immunologic targets. Understanding and modulating the cellular and molecular mechanisms governing meniscal degeneration and repair may enable the development of more effective, mechanism-driven strategies to improve healing outcomes and reduce the risk of post-traumatic osteoarthritis. Full article

Increasing emphasis is being placed on evaluating pain and mobility outcomes of osteoarthritis (OA) in both clinical and preclinical studies. In rodent models of post-traumatic OA (PTOA), particularly those utilizing destabilization of the medial meniscus (DMM), behavioral assays are becoming more prominent as researchers seek to bridge the translational gap between structural joint pathology and human disability. However, substantial variability exists in how behavior, mobility, and pain are assessed, potentially limiting reproducibility and cross-study comparisons. This review evaluates the current literature on behavioral and pain-related outcomes in rodent DMM models, with the aim of cataloging observed phenotypes, identifying methodological inconsistencies, and proposing recommendations for standardization. We compiled data on a range of behavioral assays, including mechanical and thermal sensitivity, cage monitoring, gait analysis, weight distribution, balance, and joint compression, to construct a temporal framework of post-injury changes in behavior. Across studies, behavioral changes were observed as early as one day post-injury and persisted up to 30 weeks, with notable variability depending on age, sex, and testing protocols. Young male mice (≤12 weeks old) were the most extensively studied. The findings highlight clear trends in pain sensitivity and functional decline but also underscore the need for harmonized methodologies and reporting standards. By providing a comprehensive synthesis of behavioral outcomes post-DMM, this review aims to support more informed study design and interpretation, offering a foundation for greater consistency and translational relevance in future rodent DMM research. Full article

Background/Objectives: Open reduction and internal fixation with plates and screws is the treatment of choice for bicondylar tibial plateau fractures. The use of a surgical approach remains a topic of debate regarding the site and number of incisions that ensure best access for reduction with minimum additional soft tissue damage. This retrospective cohort study compared clinical, radiological, and functional outcomes of single- (anterior) versus dual-incision (anterolateral and medial) approaches that are widely used in the operative treatment of Schatzker V–VI tibial plateau fractures. Methods: Eighty-two patients treated between 2005 and 2020 were retrospectively analyzed. Fifty-two underwent a single-incision (SI) approach and 30 a dual-incision (DI) approach. Operative parameters, complications, reduction quality, Knee Society Score (KSS), Oxford Knee Score (OKS), and post-traumatic arthritis incidence were assessed. Results: Mean patient age was 50.6 years, with a mean follow-up of 8.5 years. Operative time was shorter in the SI group, though fluoroscopy time was longer. No significant difference was observed in reduction quality or wound complications. Post-traumatic arthritis occurred in 57.6% of SI and 53.3% of DI patients, with severe arthritis more frequent in SI (30% vs. 12.5%, p < 0.05). Seven patients required conversion to total knee arthroplasty (five SI, two DI). Functional recovery was similar: mean KSS 68.6% (SI) vs. 70.5% (DI) and OKS 36.1 vs. 40.8 (p > 0.05) at 5 years. Conclusions: Both single- and dual-incision approaches for complex tibial plateau fractures provide satisfactory long-term outcomes. While differences in complications and arthritis rates were minor, surgical choice should be guided by the fracture morphology, patient characteristics, and surgeon’s experience to balance reduction quality with soft tissue preservation. Full article