Inflammatory synovitis in degenerative joint disease.

While the cartilage and bone abnormalities in osteoarthritis (OA) have been adequately described there are few prospective reviews of the histopathologic changes in OA synovia. Therefore 15 consecutive patients with OA who underwent hip or knee arthroplasty were evaluated and random samples of the synovial membranes were studied. Synovial membrane histopathologic abnormalities were present in all but 2; 9 demonstrated mild or moderate synovitis whereas 4 synovial membranes were markedly inflamed. Inflammatory synovitis is often present in OA.