Spontaneous osteoarthritis in rhesus macaques. II. Characterization of disease and morphometric studies.

From examination of the articular tissue of 35 animals from the Caribbean Primate Research Centre, we identified the epidemiological and histomorphometric features of the spontaneous osteoarthritis (OA) that affects the free-ranging rhesus macaques. The frequency of this disease increases with aging, and in females, with increased parity. Histological and morphological studies demonstrate that as in humans, the disease is characterized by persistence of the chondrocyte density typified by the cartilage of young animals. Owing to its epidemiologic and histologic resemblance to the disease in man, we conclude that degenerative arthritis affecting rhesus macaques provides a useful model for the study of factors contributing to the pathogenesis of OA.