Alterations of rabbit articular cartilage by intra-articular injections of glucocorticoids.

The destruction of rabbit articular cartilage after intra-articular injections of hydrocortisone acetate was investigated using histological, biochemical, and tracer methods. Fissures and cysts increased in number as increasing amounts of hydrocortisone were given. A linear decrease of hexosamine to less than 50 per cent after twelve injections was accompanied by insigificant changes in deoxyribonucleic acid and hydroxyproline content. The synthesis of proteoglycans and proteins was reduced to one-third, while the production of collagen dropped to less than one-fifth. The changes in thymidine incorporation were not significant. Based on these data, a model indicating the sequence of events which leads to joint destruction after intra-articular injections of glucocorticoid is proposed.