Hip involvement in juvenile rheumatoid arthritis.

We followed 386 children who met the criteria for juvenile rheumatoid arthritis (JRA) an average of 89 months. Hip involvement in JRA results in poor functional capacity. The prognosis for the pauciarticular group is good, but patients with onset at age greater than 6 years appear to do worse than those aged less than 6 years. In the polyarticular group, age of onset did not change the prognosis, whereas the systemic-onset group aged less than 6 years had a worse prognosis and more frequent radiographic changes than the older group.