Silent avascular necrosis of the femoral head in haemophilia.

Haemophilia is a rare cause of avascular necrosis of the femoral head. We report three cases from one centre, an incidence of 2.8%. All three cases presented "silently", and this makes the early diagnosis difficult. Awareness of the condition should lead to examination of the hips of haemophiliac patients at every outpatient visit and admission in the hope that hip disease can be diagnosed at an early stage. This may allow earlier treatment, less femoral head deformity, and an improvement in the long-term prognosis.