Synovial immunofluorescence in patients with slipped capital femoral epiphysis.

To evaluate if the immune system is active in slipped capital femoral epiphysis (SCFE) or chondrolysis, 16 patients with SCFE were studied by evaluation of their serum immunoglobulins, histology of their synovium, and immunofluorescent staining of their synovium. Patients with Perthes' disease, chondromalacia patellae, septic arthritis, sickle cell disease, and torn meniscus were controls. Serum immunoglobulins were normal in all patients. The histology demonstrated synovitis in all patients except in one normal knee. Plasma cells were a prominent feature of the synovitis in the patients with SCFE. Three patients had positive synovial immunofluorescence for IgG and C3. Two of these patients subsequently developed chondrolysis and one did not. One additional patient who had negative synovial immunofluorescence developed chondrolysis. It is postulated that the immune system is active in some patients with SCFE, but what, if any, role it plays in the disease or its complications remains to be shown.