DEGENERATED HUMAN ARTICULAR-CARTILAGE AT AUTOPSY REPRESENTS PRECLINICAL OSTEOARTHRITIC CARTILAGE - COMPARISON WITH CLINICALLY DEFINED OSTEOARTHRITIC CARTILAGE

Objective. To investigate whether macroscopically fibrillated human ar ticular knee cartilage observed at autopsy can be considered an early preclinical phase of osteoarthritis (OA). Methods. Histological and bi ochemical characteristics of 3 types of articular knee cartilage were compared: macroscopically degenerated knee cartilage obtained at autop sy (6 donors) from donors without clinical history of OA, normal healt hy knee cartilage obtained at autopsy (6 donors), and OA cartilage obt ained during joint replacement surgery from patients (n = 6) with clin ically defined OA of the knee, From the same donors synovial tissue an d synovial fluid were obtained and analyzed for features of inflammati on. Results. Histological changes of OA were comparable for degenerate d and OA. cartilage and significantly different from normal cartilage, Content and synthesis of proteoglycans showed intermediate levels for degenerated tissue compared to normal and OA cartilage. Analysis of s ynovial tissue revealed a low, mild, and moderate degree of inflammati on for joints with normal, degenerated, and OA cartilage, respectively . The same sequence was found for metalloproteinase activity in synovi al fluid. Conclusion. In general, all changes observed in OA joints we re, to a lesser extent, observed in the joints with degenerated cartil age and were significantly different from joints with normal cartilage . We conclude that cartilage degeneration observed at autopsy can be c onsidered a preclinical phase of OA, suitable for studying the process of cartilage degeneration in OA.