The surgical treatment of teratologic dislocation of the hip.

Since 1974, our approach to treatment of teratologic dislocation of the hip in children has been surgical. We retrospectively reviewed 20 teratologic hip dislocations in 13 children with a minimum follow-up of 2 years. Closed treatment failed in most of the hips. At a mean age of 13 months, 11 patients (18 hips) had an open reduction and a one-and-a-half hip spica. It was followed in most of these hips by a femoral varus derotational osteotomy 6 weeks later. Only three hips had an open reduction followed by 3 months of casting. One of these three hips had salmonella infection and a redislocation. Our main complication was avascular necrosis in 20% of hips, two patients (two hips) ending with a leg length discrepancy. There was some limitation of motion in 65% of hips but 76% of patients had a good functional hip score. There was no difference in the results of unilateral versus bilateral dislocation. Poor results were found in three patients and could be explained by trunk hypotonia, marked limitation of motion and severe involvement of upper extremities, multiple deformities and fixed flexion in the lower extremities, generalized weakness and developmental delay. In spite of these difficulties and complications, results are encouraging.