Search Results (303)

Background: Autologous osteochondral transplantation (AOT)—the transfer of hyaline cartilage with its underlying subchondral bone—is well established for focal osteochondral lesions, yet evidence for larger (>200 mm²) defects is limited. We assessed clinical and functional outcomes of AOT in patients with osteochondral knee lesions exceeding 200 mm². Methods: In this retrospective cohort study, 52 patients underwent AOT for full-thickness osteochondral defects of the femoral condyles or patellofemoral joint. All lesions were ≥200 mm² and treated with a standardized press-fit technique using one to four overlapping cylindrical grafts. Pain and knee function were evaluated preoperatively and at 3, 6, and 12 months postoperatively with the Visual Analogue Scale (VAS), Tegner–Lysholm Knee Score (TLKS), and Knee Society Score (KSS). Results: Mean defect size was 224.4 ± 84.5 mm². The VAS improved from 6.32 ± 1.1 preoperatively to 0.72 ± 0.6 at 12 months (p < 0.001). The TLKS rose from 58.6 ± 11.4 to 95.0 ± 6.8 and the KSS from 63.8 ± 12.2 to 97.4 ± 4.9 during the same period (both p < 0.001). Most gains occurred within the first 3–6 months and were sustained at 12 months. No major surgical complications were observed, and outcomes were unaffected by age, sex, or graft number/size. Conclusions: AOT is a safe, effective option for large osteochondral knee defects (>200 mm²), offering rapid, durable pain relief and excellent functional recovery while preserving native joint structures. Accurate donor site reconstruction and precise graft placement in the weight-bearing zone appear critical for optimal results. Longer-term prospective studies are needed to confirm durability and refine patient-selection criteria. Full article

Osteochondroses of the foot represent a unique and less frequently discussed topic. This narrative review aims to provide a comprehensive overview of foot osteochondroses, highlighting their definition, pathophysiology, clinical features, diagnosis, and treatment. Historical sources, including early case reports, were included along with the current literature to picture the current knowledge on the subject. Anatomical mapping of pain locations and associated ossification centers was employed as a framework to present the various forms of foot osteochondroses. Multiple types of foot osteochondrosis were identified. The calcaneus, navicular and lesser metatarsal are among the more common involved bones. Most forms share a multifactorial etiology involving mechanical stress, vascular insufficiency, and delayed ossification. The pain is localized and common to all forms. Diagnosis relies on clinical assessment supported by radiographic and sometimes magnetic resonance imaging findings. During the acute phase, joint rest is essential. Despite the potential for spontaneous resolution, some cases can lead to structural deformities or persistent symptoms. Foot osteochondroses, although rare, require careful clinical evaluation due to their impact on pediatric patients. Increased awareness and standardized treatment approaches may improve early recognition and management, potentially reducing long-term sequelae. Full article

Background: A trilayered collagen/collagen–magnesium–hydroxyapatite (Col/Col-Mg-HA) scaffold is used in clinical practice to treat osteochondral lesions, but the regeneration of the subchondral bone is still not satisfactory. Objective: The aim of this study was to test, in vitro, the osteoinductivity induced by the addition of bone morphogenetic protein-2 (BMP-2) or amorphous calcium phosphate granules with strontium ions (Sr-ACP), in order to improve the clinical regeneration of subchondral bone, still incomplete. Methodology: Normal human osteoblasts (NHOsts) were seeded on the scaffolds and grown for 14 days in the presence of human osteoclasts and conditioned medium of human endothelial cells. NHOst adhesion and morphology were observed with transmission electron microscopy, and metabolic activity was tested by Alamar blue assay. The expression of osteoblast- and osteoclast-typical markers was evaluated by RT-PCR on scaffolds modified by enrichment with BPM-2 or Sr-ACP, as well as on unmodified material used as a control. Results: NHOsts adhered well to all types of scaffolds, maintained their typical morphology, and secreted abundant extracellular matrix. On the modified materials, COL1A1, SPARC, SPP1, and BGLAP were more expressed than on the unmodified ones, showing the highest expression in the presence of BMP-2. On Sr-ACP-enriched scaffolds, NHOsts had a lower proliferation rate and a lower expression of RUNX2, SP7, and ALPL compared to the other materials. The modified scaffolds, particularly the one containing Sr-ACP, increased the expression of the osteoclasts’ typical markers and decreased the OPG/RANKL ratio. Both types of scaffold modification were able to increase the osteoinductivity with respect to the original scaffold used in clinical practice. BMP-2 modification seemed to be more slightly oriented to sustain NHOst activity, and Sr-ACP seemed to be more slightly oriented to sustain the osteoclast activity. These could provide a concerted action toward better regeneration of the entire osteochondral unit. Full article

Composite scaffolds based on a hydrogel matrix modified with hydroxyapatite, magnesium, or zinc compounds are promising for filling and regenerating osteochondral defects due to the specific biological properties of these modifiers. The aim of this work was to evaluate the influence of hydroxyapatite, nano-hydroxyapatite, magnesium chloride, and zinc oxide on mechanical properties, swelling ability, behavior in a simulated biological environment (ion release, stability, bioactivity), and antibacterial effects. Furthermore, the influence of the hydrogel matrix (alginate, gelatin, alginate/gelatin) on the selected properties was also assessed. The results showed that the addition of ZnO improved the mechanical properties of all types of matrices most effectively. Additionally, zinc ions were gradually released into the environment and partially incorporated into the formed apatite. The released zinc ions increased the inhibition zones of Staphylococcus aureus growth; however, this effect was observed only in scaffolds with an alginate matrix. This indicates that hydrogel plays a key role in antibacterial effects, beyond the contribution of antibacterial additives. No effect of magnesium on bacterial growth inhibition was observed despite its rapid release. Magnesium ions promoted efficient secretion of apatite during incubation, although it was not stable. The addition of nano-HAP significantly increased the stability of the apatite precipitates. Full article

Osteochondral regeneration remains a major clinical challenge due to the complex architecture and biomechanical demands of the osteochondral unit. Bioactive hydrogels have emerged as promising materials capable of supporting repair through their capacity to mimic the extracellular matrix (ECM), enable cell encapsulation, and deliver bioactive cues. However, recent insights reveal that simply engineering hydrogels for structural and cellular support is insufficient. A new paradigm is emerging—one that embraces the complexity of the osteochondral niche by integrating immunomodulatory and mechanobiological cues into biomaterial design. In particular, the hydrogel’s capacity to modulate macrophage polarization and support the immunoregulatory function of mesenchymal stem cells (MSCs) is critical to orchestrate regenerative outcomes. Simultaneously, the mechanical properties of hydrogels—such as stiffness, porosity, and viscoelasticity—can profoundly influence stem cell fate and local tissue morphogenesis. This review discusses recent advances in hydrogel-based strategies for osteochondral repair, highlighting the interplay between immunological signals and the mechanical microenvironment, and calls for a shift from reductionist tissue-engineering approaches to systems-level design of tunable, immuno-mechanobiological microenvironments. Full article

Osteochondritis Dissecans (OCD) is a joint condition characterized by damage to the surface of the joint and the underlying subchondral bone, leading to early-onset osteoarthritis. It predominantly affects the knee, elbow, and ankle, with higher prevalence in juveniles actively participating in sports, which complicates the condition due to slow healing processes and prolonged restrictions on physical activities. This review aims to summarize current knowledge on OCD in athletes, with emphasis on sport-specific risk factors, diagnosis, and treatment, to support clinical decision-making and future research. We conducted searches in the PubMed and Embase databases, covering the period from 2014 to 2024. The keywords used in the search covered most common sports in combination with term osteochondritis dissecans. This review examines the impacts of various sports on the development of OCD, analyzing prevalence and risk factors, with a focus on sports-specific risks across athletic disciplines like football, basketball, baseball, and gymnastics. The significance of early detection, intervention, and sport-specific conditioning is underscored to prevent the condition and manage it effectively. Moreover, the review highlights the positive prognosis for athletes, particularly adolescents, recovering from OCD, with a high rate of return to sport. Understanding the sports-specific risks, ensuring early intervention, and adopting a cautious, stepwise return to sport are critical for managing OCD effectively, thereby safeguarding the health and careers of athletes. Full article

Obesity, characterized by excessive or abnormal accumulation of body fat, is associated with a range of metabolic and inflammatory diseases, including osteoarthritis (OA). In obese individuals, adipose tissue expansion—via adipocyte hypertrophy or hyperplasia—is accompanied by altered secretion of adipokines such as leptin and adiponectin, which play significant roles in immune modulation, metabolism, and skeletal homeostasis. Leptin, acting through the hypothalamus, regulates the sympathetic nervous system and modulates hormonal axes, influencing bone metabolism and cartilage integrity. Elevated leptin concentrations in the synovial fluid, and the presence of its receptors on cartilage surfaces, suggest its direct role in cartilage degradation and OA progression. Conversely, adiponectin exerts anti-inflammatory effects, modulates osteoblast and macrophage activity, and appears to have a protective function in joint metabolism. These findings underscore the complex interplay between the adipose tissue, adipokines, and the osteochondral unit, highlighting the importance of their balance in maintaining joint health. Full article

Background/Objectives: The variety of magnetic resonance imaging (MRI) scales available to measure soft tissue and osteochondral changes in joints of persons with hemophilia poses challenges in evaluating published clinical/research studies. To evaluate the value of four MRI scales [(i) the 17-point International Prophylaxis Study Group [IPSG] additive scale; (ii) and (iii) the compatible IPSG progressive (P) and additive (A) scales; and (iv) the Denver progressive scale] to assess joint change in boys with hemophilia participating in a prospective two-year prophylaxis study. Methods: Boys with severe hemophilia A (ages, 7–16 years) followed at the Hospital for Sick Children, Toronto, Canada had MRI evaluations of six index joints (ankles, knees, elbows) at study entry and exit. Musculoskeletal (MSK) outcomes included in the study were the Colorado Child Physical Examination (PE) scale; the Pettersson (X-ray) scale; and the aforementioned 4 MRI scales. Results: Very strong (r ≥ 0.80) correlations were observed between the IPSG 17-point, the IPSG progressive (P) and the Denver MRI scales, and moderate (r = 0.40–0.59) to strong (r = 0.60–0.79) correlations for the IPSG 17 point and the IPSG additive (A) MRI scales. Very weak (r = 0.20–0.39) or no correlations were observed between soft tissue MRI scores and the swelling item of the Child PE scale. Conclusions: All four MRI scales demonstrated relative comparability of their construct validities for assessing mild/moderate hemophilic arthropathy. The 17-point IPSG additive scale is recommended as a reference standard in future long-term studies of young boys with hemophilia receiving factor and non-factor-based preventive therapies. Full article

Cartilage damage, particularly in the knee joint, presents a significant challenge in regenerative medicine due to its limited capacity for self-repair. Conventional treatments like microfracture surgery, autologous chondrocyte implantation (ACI), and osteochondral allografts often fall short, particularly in cases of larger defects or degenerative conditions. This has led to a growing interest in tissue engineering approaches that utilize biomaterial scaffolds to support cartilage regeneration. Among the many materials explored, chitosan—a naturally derived polysaccharide—has gained attention for its biocompatibility, biodegradability, and structural resemblance to the extracellular matrix (ECM) of cartilage. Recent advances in scaffold design have focused on modifying chitosan to improve its mechanical properties and enhance its biological performance. These modifications include chemical crosslinking, the incorporation of bioactive molecules, and the development of composite formulations. Such enhancements have allowed chitosan-based scaffolds to better support mesenchymal stem cell (MSC) differentiation into chondrocytes, paving the way for improved regenerative strategies. This review explores the latest progress in chitosan scaffold fabrication, preclinical findings, and the transition toward clinical applications. It also discusses the challenges that need to be addressed, such as mechanical stability, degradation rates, and the successful translation of research into viable therapeutic solutions. Full article

This study aimed to evaluate the effectiveness of different rehabilitation protocols following osteochondral autograft transplantation (OAT) in patients with focal osteochondral defects of the femoral condyle, using the MOCART 2.0 knee score as a primary imaging outcome. Twenty-nine patients were divided into three groups: Group 1 (n = 9) received OAT with bone marrow aspirate concentrate (BMAC) and a 12-week two-phase rehabilitation program; Group 2 (n = 11) received OAT with a 12-week program without BMAC; and Group 3 (n = 9) received OAT with a shortened 6-week program. At the 12-month follow-up, Group 1 demonstrated a superior cartilage repair quality, with the highest mean MOCART 2.0 score (96.1), compared to Group 2 (80.2) and Group 3 (71.7). Notably, complete defect filling was observed in five patients in Group 1 versus four in Group 2 and only one in Group 3. The integration and surface integrity were also better preserved in Group 1. The addition of BMAC and an extended, progressive rehabilitation protocol significantly enhanced the morphological cartilage repair parameters. These results suggest that a biologically enhanced and prolonged recovery plan may offer a greater structural restoration of cartilage after OAT than conventional or accelerated protocols. Full article

Bone marrow stimulation is a treatment for articular cartilage injuries that promotes cartilage repair by inducing the migration and accumulation of mesenchymal stem cells (MSCs), but often results in fibrocartilage with limited durability. This study aimed to investigate the effect of hypoxic conditions on cartilage repair using a rat osteochondral defect model. Osteochondral defects (1.0 mm in diameter) were created in the femoral trochlear groove, and rats were exposed to hypoxic conditions (12% O₂) for 4 weeks postoperatively. Histological analysis was performed, and protein expression of hypoxia-inducible factor-1α (HIF-1α) and SRY-box transcription factor 9 (SOX9) in the repair tissue was evaluated after 1 week. As a result, after 1 week, protein expression of HIF-1α and SOX9 in the Hypoxia group was significantly increased compared to the Normoxia group. After 4 weeks, the Hypoxia group exhibited a hyaline cartilage-like tissue structure with a significantly lower Modified Wakitani score compared to the Normoxia group. Furthermore, after 4 weeks, the inhibition of HIF-1α suppressed cartilage repair. These findings suggest that hypoxic conditions promote SOX9 expression via HIF-1α during the early phase of MSC chondrogenic differentiation and promote the formation of hyaline cartilage-like repair tissue. In conclusion, bone marrow stimulation under hypoxic conditions may enhance the repair effect on articular cartilage injuries. Full article

Due to the limited regeneration of cartilage, new implant materials are needed. Biodegradable polymers poly-(D,L)-lactide-ε-caprolactone-methacrylate (LCM) and polyamid-ε-caprolactone-methacrylate (ACM) were recently established and coated with heparin, making them able to prevent blood coagulation and cartilage mineralization. The aim of this study was to analyze the suitability of LCM and ACM alone or coated with heparin (the latter are abbreviated as LCMH and ACMH, respectively) as implant material for cartilage repair. Therefore, mesenchymal stem cells were chondrogenically differentiated in 2D cultures with polymer discs. Differentiation was induced by the supplementation of cell medium with dimethyloxalylglycine, TGF-β, and BMP2. After 5 days, no increase in proinflammatory factors was observed. Cell viability declined on ACM and ACMH discs. During early chondrogenesis, SOX9 expression increased on LCM and LCMH discs, while TRPV4 expression decreased on ACMH discs. At day 20, the level of collagen type II increased on LCM, LCMH, and ACM discs, demonstrating the ability of chondrogenic development on these implants. In summary, coating with heparin showed no advantages compared to pure LCM and ACM. For cartilage repair, LCM is more suitable than ACM in this 2D in vitro model, which needs to be verified by long-term 3D models and in vivo studies. Full article

Osteoarthritis (OA) is the most prevalent degenerative joint disorder worldwide, causing significant declines in quality of life. The osteochondral junction (OCJ), a critical structural interface between deep cartilage and subchondral bone, plays an essential role in OA progression but is challenging to assess using conventional magnetic resonance imaging (MRI) due to its short T2 relaxation times. This study aimed to evaluate the utility of ultrashort echo time (UTE) MRI biomarkers, including macromolecular fraction (MMF), magnetization transfer ratio (MTR), and T2*, for in vivo quantification of OCJ changes in knee OA for the first time. Forty-five patients (mean age: 53.8 ± 17.0 years, 50% female) were imaged using 3D UTE-MRI sequences on a 3T clinical MRI scanner. Patients were stratified into two OA groups based on radiographic Kellgren–Lawrence (KL) scores: normal/subtle (KL = 0–1) (n = 21) and mild to moderate (KL = 2–3) (n = 24). Quantitative analysis revealed significantly lower MMF (15.8  ±  1.4% vs. 13.6 ± 1.2%, p < 0.001) and MTR (42.5 ± 2.5% vs. 38.2  ±  2.3%, p < 0.001) in the higher KL 2–3 group, alongside a higher trend in T2* values (19.7  ±  2.6 ms vs. 21.6  ±  3.8 ms, p = 0.06). Moreover, MMF and MTR were significantly negatively correlated with KL grades (r = −0.66 and −0.59; p < 0.001, respectively), while T2* showed a weaker positive correlation (r = 0.26, p = 0.08). Receiver operating characteristic (ROC) analysis demonstrated superior diagnostic accuracy for MMF (AUC = 0.88) and MTR (AUC = 0.86) compared to T2* (AUC = 0.64). These findings highlight UTE-MT techniques (i.e., MMF and MTR) as promising imaging tools for detecting OCJ degeneration in knee OA, with potential implications for earlier and more accurate diagnosis and disease monitoring. Full article

Understanding the complex mechanical behavior of osteochondral tissues in silico is essential for improving experimental models and advancing research in joint health and degeneration. This review provides a comprehensive analysis of the constitutive models currently used to represent the different layers of the osteochondral region, from articular cartilage to subchondral bone, including intermediate regions such as the tidemark and the calcified cartilage layer. Each layer exhibits unique structural and mechanical properties, necessitating a layer-specific modeling approach. Through critical comparison of existing mathematical models, the viscoelastic model is suggested as a pragmatic starting point for modeling articular cartilage zones, the tidemark, and the calcified cartilage layer, as it captures essential time-dependent behaviors such as creep and stress relaxation while ensuring computational efficiency for initial coupling studies. On the other hand, a linear elastic model was identified as an optimal starting point for both the subchondral bone plate and the subchondral trabecular bone, reflecting their dense and stiff nature, and providing a coherent framework for early-stage multilayer integration. This layered modeling approach enables the development of physiologically coherent and computationally efficient representations of osteochondral region modeling. Furthermore, by establishing a layer-specific modeling approach, this review paves the way for modular in silico simulations through the coupling of computational models. Such an integrative framework supports scaffold design, in vitro experimentation, preclinical validation, and the mechanobiological exploration of osteochondral degeneration and repair. These efforts are essential for deepening our understanding of tissue responses under both physiological and pathological conditions. Ultimately, this work provides a robust theoretical foundation for future in silico and in vitro studies aimed at advancing osteochondral tissue regeneration strategies. Full article

Background: There are a few very specific inflammation biomarkers in blood, namely lipoprotein NMe⁺ signals of protein clusters (GlycA and GlycB) and a composite resonance of phospholipids (SPC). The relative integrals of these resonances provide clear indication of the unique metabolic changes associated with disease, specifically inflammatory conditions, often related to serious diseases such as cancer or COVID-19 infection. Relatively complicated, yet very efficient experimental methods have been introduced recently (DIRE, JEDI) to suppress the rest of the spectrum, thus allowing measurement of these integrals of interest. Methods: In this study, we introduce a simple alternative processing method using CRAFT (Complete Reduction to Amplitude-Frequency Table), a time-domain (FID) analysis tool which can highlight selected subsets of the spectrum by choice for quantitative analysis. The output of this approach is a direct, spreadsheet-based representation of the required peak amplitude (integral) values, ready for comparative analysis, completely avoiding all the convectional data processing and manipulation steps. The significant advantage of this alternative method is that it only needs a simple water-suppressed 1D spectrum with no further experimental manipulation whatsoever. In addition, there are no pre/post processing steps (such as baseline and/or phase), further minimizing potential dependency on subjective decisions by the user and providing an opportunity to automate the entire process. Results: We applied this methodology to horse serum samples to follow the presence of inflammation for cohorts with or without OCD (Osteochondritis Dissecans) conditions and find diagnostic separation of the of the cohorts through statistical methods. Conclusions: The powerful and simple CRAFT-based approach is suitable to extract selected biomarker information from complex NMR spectra and can be similarly applied to any other biofluid from any source or sample, also retrospectively. There is a potential to extend such a simple analysis to other, previously identified relevant markers as well. Full article