[Ultrasonography of hips in neonates].

For evaluation of the development of the hip joints in young infants, between Jun., 1988 and Oct., 1991, 522 hips of the infants under 4 months of age were studied by ultrasonography based on the method well described by Graf. The results revealed only 48% of the hips of neonatal group was type I (stable type). But this percentage increased with age: 90% in the group under 2 months of age; 97% in the group under 4 months of age. Compared with the findings of other studies in Europe, the development and the stability of the hips of our neonatal group seemed poorer. But this condition improved much within 2 months after birth. So we concluded that, except the high risk group, the ultrasonographic screening approach should be performed after 2 months of age, but not in neonatal period under considering the cost-benefit.