Effect of intra-articular corticosteroid injections on primate cartilage.

An attempt was made to ascertain whether intra-articular corticosteroids exert a harmful effect on primate cartilage. The knee joints of 10 Macaca irus monkeys were subjected to either one, two, or six injections of 20 mg methyl prednisolone or an equal number of control injections over a 12-week period. Minor degenerative changes of many femoral condyles were shown by India ink staining and by a system of histochemical grading. Changes in the joints injected with corticosteroid were not significantly different from those seen in control joints. The findings were in striking contrast to the severe degeneration reported by others in rabbit joints injected with corticosteroid. The experiment did not support the contention that intra-articular corticosteroids invariably have a deleterious effect on primate cartilage.