The treatment of developmental dysplasia of the hip diagnosed after the first year of life remains controversial. A series of 36 children (47 hips), aged between one and 4.9 years underwent gradual closed reduction using the Petit-Morel method. A pelvic osteotomy was required in 43 hips (91.5%). The patients whose hips did not require pelvic osteotomy were among the youngest. The mean age at final follow-up was 16.1 years (11.3 to 32). The mean follow-up was 14.3 years (10 to 30).

At the latest follow-up, 44 hips (93.6%) were graded as excellent or good according to the Severin classification. Closed reduction failed in only two hips (4.3%) which then required open reduction. Mild avascular necrosis was observed in one (2.1%).

The accuracy of the reduction and associated low complication rate justify the use of the Petit-Morel technique as the treatment of choice for developmental dysplasia of the hip in patients aged between one and five years.

Rocker bottom deformity may occur during the conservative treatment of idiopathic congenital clubfoot. Between 1975 and 1996, we treated 715 patients (1120 clubfeet) conservatively. A total of 23 patients (36 feet; 3.2%) developed a rocker bottom deformity. It is these patients that we have studied. The pathoanatomy of the rocker bottom deformity is characterised by a plantar convexity appearing between three and six months of age with the hindfoot equinus position remaining constant. The convexity initially involves the medial column, radiologically identified by the talo-first metatarsal angle and secondly by the lateral column, revealed radiologically as the calcaneo-fifth metatarsal angle. The apex of the deformity is usually at the midtrasal with a dorsal calcaneocuboid subluxation. Ideal management of clubfoot deformity should avoid this complication, with adequate manipulation and splinting and early Achilles’ percutaneous tenotomy if plantar convexity occurs.

Adequate soft-tissue release provides satisfactory correction for rocker bottom deformity. However, this deformity requires more extensive and complex procedures than the standard surgical treatment of clubfoot. The need for lateral radiographs to ensure that the rocker bottom deformity is recognised early, is demonstrated.