[Natural history of hip necrosis in sickle cell disease. Apropos of 104 necroses].

The authors have followed 140 patients with sickle cell disease anemia (101 cases) or related hemoglobinopathies (39 cases). Among them hip involvement was noted in 55 (104 hips). Forty three times the hip involvement occurred in childhood and twelve times in adult life. When the necrosis appeared in childhood (84 hips) the average age was twelve. The deformity involved the femoral head (coxa plana, coxa magna) as well as the neck (short neck, coxa vara). After an average follow-up of nineteen years, clinical and radiological examinations evidenced 64 functional impairments and 25 arthrosis, 10 of which have already been operated on. The necrosis appearing during adult life (20 hips) had the same outcome as idiopathic necroses, leading rapidly to arthrosis after collapse of the sequestrum. It seems that the etiology of the necroses is linked to rheologic disorders, the deformity of the red cells causing arteriolar thromboses. In this series the hip disease was correlated with sickle cell retinopathy as defined after angiography. On the contrary there was no correlation with the severity of anemia, its treatment, the ethnical origin of the patient.