The pathogenesis of chronic haemophilic synovitis and the destructive capabilities of the synovium are multifactorial. As a result of repeated haemarthroses, synovial hyperthrophy occurs, iron and cellular debris are phagocytized, and hydrolytic enzymes synthesized by the proliferating synovium are released into the joint. An inflammatory process develops, and the nutrition of the articular cartilage is affected by the abnormal synovial fluid, immobilization of the joint, and the presence of fibrous adhesions. Chronic hypertrophic synovitis is a progressive destructive condition in the joint and, unless it is treated, the joint is doomed. With the development of cartilaginous destruction, progressive chondrolysis and eventual osteoarthritis set in.