Comparison of Self-repair Disparities in Articular Cartilage Defect Models With Various Load-bearing Sites

This study aimed to explore the construction of experimental animal models replicating cartilage defects across diverse load-bearing sites, compare self-repair conditions, and examine the role of mechanical stimulation in cartilage self-repair. Experimental animal models were established in rabbits to simulate full-thickness cartilage defects without penetrating the subchondral bone, at various load-bearing sites, including the posterior femoral condyle, anterior femoral condyle and femoral trochlear of knee joint, and the humerus of the shoulder joint. The successful exposure and construction of cartilage defects at the anterior femoral condyle, femoral trochlear, and posterior femoral condyle through the medial extension of surgical incision. In addition, a fully non-loaded articular cartilage defect could be constructed in the shoulder joint of the upper limb using a specific surgical approach. No mortality or disability was observed in the experimental animals after the surgeries. At the 8-week sampling period postsurgery, the defect sites showed the growth of hyaline tissues. The repair effects were ranked in the following order from good to poor; posterior femoral condyle, anterior femoral condyle, femoral trochlear, and humerus. The application of suitable compressive loads under normal load-bearing conditions has been found to positively impact the repair of articular cartilage.