Histological cartilage changes in a rabbit model of osteoarthritis

The anterior cruciate ligament was severed in the right knee of 36 rabbits which were then killed 12 weeks after surgery. Changes in water content and fixed charge density were correlated with the surface area of induced cartilage fibrillation. Histological changes including cartilage hypertrophy, reduced cell density, matrix alterations, cystic lesions, and enlarged perichondrocytic lacunae were found to precede cartilage fibrillation. The observed histological changes are in agreement with an enzymatic degradation of articular cartilage in osteoarthritis.