Ultrasonography in the diagnosis of congenital hip dysplasia in the newborn.

A new technique for ultrasonic examination of the hip is aimed at identification of the acetabular cartilaginous ridge, called the "neolimbus" by Ortolani. The presence of this ridge is pathognomonic for congenital hip dysplasia in the newborn. Ultrasonography of 300 normal hips never showed the neolimbus, but it was present in 25 dysplastic hips. Ultrasound examination of the hips of newborn infants can therefore be combined with the Ortolani test in the very early diagnosis of hip dysplasia.