Osteoarthritis (OA) of the knee joint is a complex peripheral joint disorder with multiple risk factors. We aimed to examine the relationship between the grade of knee OA and anterior thigh length (ATL). A total of 64 geriatric patients who had no total hip or knee replacement with a BMI of ≥30 were evaluated. Patients' OA severity was determined by two independent experts from bilateral standing knee radiographs according to the Kellgren-Lawrence (KL) grade. Joint cartilage structure was assessed using ultrasonography (US). The ATL, the gastrocnemius medialis (GC), the rectus femoris (RF) and the rectus abdominis (RA) skeletal muscle thicknesses as well as the RF cross-sectional area (CSA) were measured with US. Sarcopenia was diagnosed using the handgrip strength (HGS), 5× sit-to-stand test (5xSST) and bioelectrical impedance analysis. The median (IQR) age of participants was 72 (65–88) years. Seventy-one per cent of the patients (n=46) were female. They were divided into the sarcopenic obese (31.3 %) and the non-sarcopenic obese (68.8%) groups. KL grade of all patients correlated negatively with the ATL (mm) and the thickness of GC (mm) (r= -0,517, p<0.001 and r= -0.456, p<0.001, respectively). In the sarcopenic obese and the non-sarcopenic obese groups, KL grade of the all patients was negatively correlated with ATL (mm) and thickness of GC (mm) (r= -0,986, p<0.001; r= -0.456, p=0.05 and r= -0,812, p=0.002; r= −0,427, p=0.006). KL grade negatively correlated with the RF thickness in the sarcopenic obese group (r= -0,928, p=0.008). In conclusion, OA risk may decrease as the lower extremity skeletal muscle mass increases. Acknowledgments: Feza Korkusuz MD is a member of the Turkish Academy of Sciences (TÜBA)

Lesions in the joint surface are commonly treated with osteoarticular autograft transfer system (OATS), autologous cell implantation (ACI/MACI), or microfracture. Tissue formed buy the latter commonly results in mechanically inferior fibrocartilage that fails to integrate with the surrounding native cartilage, rather than durable hyaline cartilage. Fractional laser treatment to make sub-millimeter (<500 µm) channels has been employed for tissue regeneration in the skin to facilitate rejuvenation without typical scarring. Additionally, we have pioneered a means to generate articular cartilage matrix from chondrocytes—dynamic Self-Regenerating Cartilage (dSRC). Combining these two approaches by performing fractional laser treatment of the joint cartilage and treating with dSRC is a new paradigm for joint surface restoration. This approach was refined in a series of in vitro experiments and tested in swine knee defects during a 6-month study in 12 swine. dSRC are generated by placing 10. 7. swine knee chondrocytes into sealed 15-mL polypropylene tubes and cultured on a rocker at 40 cycles per minute for 14 days at 37°C. The chondrocytes aggregate and generate new extracellular matrix to form a pellet of dSRC. Channels of approximately 300-500 µm diameter were created by infrared laser ablation in swine cartilage (in vitro) and swine knees (in vivo). The diameter and depth of the ablated channel in the cartilage was controlled by the light delivery parameters (power, spot size, pulse duration) from a fractional 2.94 µm Erbium laser. The specimens were evaluated with histology (H&E, safranin O, toluidine blue) and polarized-sensitive optical coherence tomography for collagen orientation. We can consistently create laser-ablated channels in the swine knee and successfully implant new cartilage from dSRC to generate typical hyaline cartilage in terms of morphology and biochemical properties. The neocartilage integrates with host cartilage in vivo. These findings demonstrate our novel combinatorial approach for articular cartilage rejuvenation

Introduction. Osteoarthritis (OA) causes pain, stiffness, and loss of function due to degenerative changes in joint cartilage and bone. In some forms of OA, exercise can alleviate symptoms by improving joint mobility and stability. However, excessive training after joint injury may have negative consequences for OA development. Sensory nerve fibers in joints release neuropeptides like alpha-calcitonin gene-related peptide (alpha-CGRP), potentially affecting OA progression. This study investigates the role of alpha-CGRP in OA pathogenesis under different exercise regimen in mice. Method. OA was induced in C57Bl/6J WT mice and alpha-CGRP KO mice via surgical destabilization of the medial meniscus (DMM) at 12 weeks of age (N=6). Treadmill exercise began 2 weeks post-surgery and was performed for 30 minutes, 5 days a week, for 2 or 6 weeks at intense (16 m/min, 15° incline) or moderate (10 m/min, 5° incline) levels. Histomorphometric assessment of cartilage degradation (OARSI scoring), serum cytokine analysis, immunohistochemistry, and nanoCT analysis were conducted. Result. OARSI scoring confirmed OA induction 4 weeks post-DMM surgery, with forced exercise exacerbating cartilage degradation regardless of intensity. No significant genotype-dependent differences were observed. Serum analysis revealed elevated cytokine levels associated with OA and inflammation in KO mice compared to WT mice 4 and 8 weeks post-surgery (VEGF-A, MCP-1, CXCL10, RANTES, MIP1-alpha, MIP1-beta, and RANKL). The observed effects were often exacerbated by intense exercise but rarely by DMM surgery. NanoCT analysis demonstrated increased sclerotic bone changes after 6 weeks of forced exercise in KO mice compared to WT mice. Conclusion. Our results suggest an OA promoting effect of exercise in early disease stages of posttraumatic OA. Intense exercise induced inflammatory processes correlated to increased cytokine levels in the serum that might exacerbate OA pathogenesis in later stages. The neuropeptide alpha-CGRP might play a role in protecting against these adverse effects

Summary. In a rabbit model of early osteoarthritis, structural changes in femoral condyle cartilage were severer in the lateral compartment and preceded alterations in the underlying bone. In the medial compartment, altered bone properties occurred together with structural changes in cartilage. Introduction. Early osteoarthritic changes in cartilage have been previously studied through anterior cruciate ligament transection (ACLT) in rabbits. However, parallel changes in the structure of subchondral and trabecular bone at 4 weeks after ACLT are not known. Methods. Skeletally mature 14-month old New Zealand white rabbits (n=8) underwent ACLT in the left knee, while right knees were used as controls (CTRL). Femoral condyles (FCs) were harvested at 4 weeks after ACLT. INDENTATION TESTING. Stepwise stress-relaxation tests were performed on medial and lateral FC cartilage (100%/s ramp rate, 3×5% step, 15 min relaxation time). Sinusoidal loading was then applied (amplitude 4% of thickness, 1Hz, 4 cycles). Equilibrium (Eeq) and dynamic (Ed) moduli were derived from stress-relaxation and sinusoidal tests, respectively. STRUCTURAL ANALYSIS OF CARTILAGE. Polarised light microscopy (PLM) and digital densitometry (DD) were used to analyze the collagen orientation angle (COA) and proteoglycan content in the cartilage samples. STRUCTURAL ANALYSIS OF BONE. Distal compartments of FCs were scanned using a high-resolution µCT scanner (Skyscan 1172, Belgium) with an isotropic voxel size of 25 µm. µCT data were imported into Mimics (Materialise, Belgium) for segmentation. 2×2×4 mm. 3. volumes of interest (VOIs) were placed in weight-bearing regions of medial and lateral FCs. Subchondral bone plate thickness (Pt.Th), trabecular volume fraction (BV/TV), trabecular thickness (Tb.Th), structural model index (SMI) and trabecular separation (Tb.Sp) were calculated using the CTAnalyzer software (Skyscan) from the VOIs. STATISTICAL TESTS. Mixed linear model for cartilage parameters and Wilcoxon signed-rank test for bone parameters were used to compare ACLT and CTRL groups (p < 0.05). Results. In both lateral and medial FC compartments, Eeq was significantly smaller in ACLT than in CTRL cartilage. In the medial compartment, also Ed was significantly smaller in ACLT than in CTRL cartilage. As a result of ACLT, significant alterations in the COA extended deeper into cartilage in the lateral than medial compartment, while proteoglycan content was reduced significantly and similarly in both lateral and medial FC cartilages. After ACLT, Pt.Th was significantly reduced in the medial compartment, while no changes were observed in the lateral compartment. Furthermore, only in the medial compartment, both BV/TV and Tb.Th were significantly smaller in the ACLT compared to the CTRL group. Discussion. The study showed that disruption of the collagen architecture in the ACLT joint cartilage extended into the middle zone only in the lateral FC compartment. Instead, thinning of the subchondral bone plate combined with resorption of trabecular bone was observed only in the medial FC compartment. The former finding reflects early osteoarthritic changes, while the latter finding may be indicative of a diminished loading in the medial FC compartment, as caused by ACLT

Objectives

In this study, we compared the pain behaviour and osteoarthritis (OA) progression between anterior cruciate ligament transection (ACLT) and osteochondral injury in surgically-induced OA rat models.

Objectives

During open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying in vivo are poorly understood. We used an animal model to investigate the subsequent effects of joint drying on cartilage and chondrocytes.

We examined osteochondral autografts, obtained at a mean of 19.5 months (3 to 48) following extracorporeal irradiation and re-implantation to replace bone defects after removal of tumours. The specimens were obtained from six patients (mean age 13.3 years (10 to 18)) and consisted of articular cartilage (five), subchondral bone (five), external callus (one) and tendon (one). The tumour cells in the grafts were eradicated by a single radiation dose of 60 Gy. In three cartilage specimens, viable chondrocytes were detected. The survival of chondrocytes was confirmed with S-100 protein staining. Three specimens from the subchondral region and a tendon displayed features of regeneration. Callus was seen at the junction between host and irradiated bone.