Natural history of advanced osteoarthritis of the hip.

We followed long-term osteoarthritis of the hip clinically and radiographically in 38 patients (47 hips) finally reaching an advanced or terminal stage for more than 10 years. The relation between various measured parameters and disease progression and osteophyte formation was analyzed. By multivariate analysis, the clinical outcome of osteoarthritis of the hip could be correctly predicted in 91.5% of cases. In the cases in which initially the slope of the acetabular roof was not steep, the greater trochanter was low, and the cranial joint space was narrow, good roof osteophyte formation was well recognized. The cases with good roof osteophyte formation were characterized by preserved roundness of the femoral head, no shortening of the femoral neck, no lateralization of the femoral head, unchanged cranial joint space, and no worsening of pain at the final follow-up.