Twenty-five patients with thirty congenitally dislocated hips in which
avascular necrosis developed after closed reduction were followed for an
average of thirty-nine years from the time of reduction. Twenty-four of the
thirty hips had moderate or severe osteoarthritis and twenty-two of the
twenty-five patients had significant pain or loss of function, or both, by
the time they were forty-two years old, The deformities produced by
avascular necrosis that were related to osteoarthritis included: (1) loss
of sphericity of the femoral head, (2) persistent lateral and proximal
subluxation, (3) irregularity of the medial part of the femoral head, and
(4) acetabular dysplasia. The study suggests that if avascular necrosis
develops following closed reduction of a congenitally dislocated hip,
attempts should be made to prevent lateral and proximal subluxation of the
femoral head and to correct thse abnormalities, if possible, once they
occur.