Magnetic resonance imaging of the femoral head to detect avascular necrosis in active rheumatoid arthritis treated with methylprednisolone pulse therapy.

Efficacious management of patients with avascular necrosis of bone (AVN) necessitates the identification of patients with a high risk of collapse of the femoral head. In this prospective study we imaged both hips of 10 patients with active rheumatoid arthritis, who were treated with methylprednisolone pulse therapy. MRI and conventional radiography were performed before MP-pulse therapy and 6 and 12 months thereafter. Two patients showed unilateral changes, compatible with AVN. One patient became symptomatic and revealed characteristic radiographic abnormalities. The other patient remained asymptomatic and the MRI appearance returned to normal after 6 months.