Ultrasonography of the infant hip. Part III: Clinical application.

We report on our results of ultrasonography of the infant hip over 2 years. Twenty-three percent of patients with abnormal sonogram showed no clinical suggestion of hip disorder. Suspicion of dislocation based on mobility, asymmetrical trochanteric distance, click or snapping of the hip and inhibited abduction were the most useful clinical criteria predicting disease in 93%, 19% and 16%, respectively. Breech presentation and family history of hip dysplasia or dislocation were important anamnestic data (21% and 16% predictive value, respectively). The significantly shorter duration of therapy in early detected dislocation or dysplasia makes the need for early diagnosis of these disorders obvious. Special emphasis lies on the physiological maturation of the acetabulum and the femoral ossification center. Normal ranges of important diagnostic criteria and angles depending on chronological age are presented.