ACETABULAR NOTCH

Ultrasound images of dysplastic and/or unstable hips often display an indentation or notch at the superolateral part of the acetabulum where the iliac wing joins the acetabular roof. We reviewed the ultrasound and subsequent radiographic examinations of 295 babies examined in our hip screening clinic. Of the hips with a notch demonstrable at the fi rst ultrasound, 97% had a persistent notch at the second ultrasound an d in 79% the notch was apparent on the 3-month radiograph. When the no tch persists, we believe that it represents damage to the lateral acet abular ring epiphysis and delayed maturation of the lateral acetabulum .