The results of the Ferguson medial approach for open reduction of developmental dysplasia of the hip (DDH) were reviewed for 49 hips with a follow-up of more than 48 months. The mean age at operation was 12.3 months (6 to 23). The mean length of clinical and radiological follow-up was 82 months (48 to 148). Three redislocations occurred. Group I avascular necrosis according to the classification of Kalamchi and MacEwen was seen in four hips, group II in two hips and group III in one hip; 92% of the hips were classified as Severin class I and II. The acetabular index and centre edge (CE) angles were within normal limits at final follow-up, but were still significantly different from the unaffected side.

We conclude that the Ferguson procedure is safe and reliable for low dislocations in children aged six to 18 months.

The results of the Ferguson medial open reduction of the hip for DDH were reviewed to determine the complications, re-operation rate, clinical and radiological outcome. Notes were reviewed for 75 cases, of which 5 were bilateral. X-rays were available for 69 hips and were analysed for Acetabular index (AI) and Centre Edge (CE) angles of the operated and unaffected hips. The hips were assessed for avascular necrosis by the method of Kalamchi and MacEwan and were graded according to Severin.

The mean age at operation was 11.8 months (range 3-23, SD 4.42, mode 11). The mean clinical follow up was 65.1 months (range 4-148, SD 33.4). The mean radiological follow up was 58.2 months (range 3 – 131, SD 31). No further surgical procedure was required for 60 hips (75%). Of the remainder, a Salter osteotomy was performed for 8 hips, of which 6 had additional procedures. 8 hips required a femoral osteotomy, 2 an Arthrogram and one a triple pelvic osteotomy.

The AI improved following surgery, with a rate of increase double that for the unaffected side. The mean centre edge of the operated side was 6 degrees less than the unaffected side. Tables 2 and 3 show that the majority of hips had no avascular necrosis and a good radiological outcome. The results compare favourably with the literature. The conclusion is that the Ferguson medial open reduction has good long-term results with low rates of avascular necrosis.