Haemophilic arthropathy of the hip in children--prognosis and long-term follow-up.

The aim of this study was to report on the long-term follow-up of haemophilic children with avascular femoral head necrosis and to determine whether radiographic findings at initial diagnosis have any prognostic value. Seven patients with avascular necrosis of the femoral head were clinically and radiographically observed over a period of 5-50 years. The average age of patients at first diagnosis was 7.1 years. At follow-up, three of seven patients claimed to have occasional mild pain in the affected hip, four of seven showed loss of range of motion in the hip joint and two of seven patients showed a limp. Only one patient was clinically completely inconspicuous. The radiographically measured caput-collum-diaphysis angle at follow-up was pathologic in four cases and in one case a lateral subluxation of the femoral head was found. There was marked deformation of the femoral head in three of seven cases and a further two hips showing slight incongruency. Owing to the small patient-number, a statement concerning the prognostic value of defined radiographic signs cannot be made. As expected, the more 'risk signs' radiographically found, the higher the likelihood that patients will suffer arthrosis at a later stage. We propose that a clear distinction between haemophilic arthropathy of the hip and Legg-Calvé-Perthes disease should be made. In cases where radiographic changes are also found in the vicinity of the acetabulum, it is indicative for haemophilic arthropathy.