MANY OF US whose formal medical education was obtained more than ten years ago may, as a result, approach the problem of congenital dislocation of the hip (hereafter CDH) with concepts whic could profitably be abandoned.
In many medical centers, CDH has been considered a consequence of failure of development of the acetabulum (acetabular dysplasia). It was usually recognized in the infant around the time of standing or walking, confirmed by radiologic examination, and treated by various types of restraining apparatus designed to replace the dislocated femoral head in proper relationship to the acetabular cavity, and to maintain it there for a period of months at least. The management in older children required hospitalizations for prolonged traction , forceful manipulation and plaster casts, radiographs, and changes of casts. And, in as many as 30% of the children, the involved hip, even if replaced, failed to develop properly so that aseptic necrosis of the femoral head (Legg-Calve-Perthe's disease) occurred and osteo-arthritis was frequent in adult life.
Early diagnosis and treatment has been the goal of orthopedic surgeons for at least the last 30 years. Pediatricians have been instructed to look for abnormal body contours, shortening of a lower extremity, asymmetrical skin folds in groins and thighs, and limitation of motion of the involved hip. When any of these still useful clinical signs were observed, radiographs of the hips were requested for measurements of acetabular angles.
In 1956, Coleman and Caffey independently challenged the validity of the available "standards" for acetabular angles, some of which were based on measurements from as few as 23 children. Caffey's report is the most extensive study to date and the most reliable statistically.