Osteonecrosis of the femoral head after acute rheumatic Fever.

An 11-year-old patient is described who developed osteonecrosis (ON) of the femoral head 4 months after an episode of arthritis of the hip associated with acute rheumatic fever. ON has been reported to occur after transient synovitis. We believe this is the first report of osteonecrosis after acute rheumatic fever and suggest that rheumatic arthritis, like transient synovitis occurring in the hip, might be a predisposing factor for the subsequent development of ON. In a patient with acute rheumatic fever and hip pain, a radiograph should be obtained early to rule out underlying pathology. If hip symptoms persist, ON should be considered, and a bone scan or magnetic resonance imaging examination should be performed.