Chondrolysis in Arthritis

Articular cartilage is composed of cells surrounded by a matrix of protein-chondroitin sulphate complex. It is nourished by diffusion from the synovial fluid. It is probable that synovial fluid is a dialysate of plasma, to which another mucopolysaccharide-protein complex containing hyaluronic acid-has been added by synovial cells. Synovial fluid does not contain fibrinogen (Ropes and Bauer 1953) unless the permeability of adjacent vessels is increased by trauma or inflammation. After these events fibrin clots may be found but they do not persist. What is the mechanism by which fibrin is removed from joint surfaces? Our own studies have shown that whenever there is fibrinogen there is plasminogen in synovial fluid; Astrup (personal communication) has demonstrated the presence of plasminogen activator in synovial tissue, and I have found that cartilage per se will also activate plasminogen (Fig. 1). Conditions such as trauma and inflammation that