histological changes were degeneration of the articular cartilage matrix , chondrocyte necrosis , flaking and fibrillation , chondrone formation , erosions and ulcers of the articular cartilage with subchondral bone sclerosis , vascular invasion with fibrosis , and chronic , nonsuppurative , proliferative synovitis .
C0022417
articular
C0007303
articular cartilage