Involvement of the hips in juvenile rheumatoid arthritis

Rheumatoid coxitis occurring in childhood develops differently from that occurring at an adult age. Inflammation quickly leads to considerable stiffness, and even to bony ankylosis, but does not cause extensive destruction. The functional disturbances set up by the inflammation interfere with the development of the hip joints, and the extent of the resultant morphologic abnormalities depends on the earliness of onset and the severity of the disturbances. Luxation and subluxation due to malformations in severe coxitis developed before the age of eight contrast with the acetabular protrusion of destructive coxitis in the adult.