Morphologic features of congenital acetabular dysplasia: one in six is retroverted.

It generally is thought that in congenital hip dysplasia, the opening of the acetabulum lies in excessive anteversion from the sagittal plane. Although this is true for the majority of patients, we found that one in six patients with acetabular dysplasia has retroversion in which the superior 1/3 of the acetabulum faces posterolaterally. Our method of analysis depends mainly on one true orthograde view of the pelvis. This view can be obtained easily and has the advantage of allowing the surgeon to adjust the correction during surgery. In the dysplastic hip with acetabular retroversion, realignment osteotomy still may be done but the corrective maneuvers are different.