Significance of preoperative position of the femoral head in failed closed reduction in developmental dislocation of the hip: Surgical results

Long-term follow-up results of open reduction for developmental dislocation of 83 hips via the extensive anterolateral approach were retrospectively analyzed. Open reduction was performed in infancy, and the follow-up period ranged from 12 to 24 years. This procedure is a complete circumferential dissection of the joint capsule and produces sufficient concentric reduction of the femoral head in the acetabulum immediately after the surgery. A lateral arthrographic classification of interposed limbus and the preoperative position of the unreduced femoral head is introduced, and is related to operative findings and surgical results, including Severin's classification. The results at the final follow-up were: Severin's group I in 35 hips, group II in 19 hips, group III in 10 hips, and group IV in four hips. According to the classification of the preoperative position of the femoral head, there were 31 hips of the intracapsular type and 37 hips of the extracapsular type. Thirty-four of the 37 hips of the extracapsular type were classified in Severin's group I or II (92%). Twenty of the 31 hips of the intracapsular type were classified in Severin's group I or II (65%). A very significantly greater number of hips with good radiological outcome were in the extracapsular type than in the intracapsular type.