RÉSUMÉ
PURPOSE: To evaluate the outcome of treatment for developmental dislocation of the hip (DDH) in children in whom the treatment was delayed until they were 6 to 24 months old. MATERIALS AND METHODS: Fifty two hips of 48 children between 6 and 24 months old, who have not been treated for DDH were selected for this study. The treatments for these children were closed reduction in 16 hips and open reduction in 36 hips. Patients were followed-up for 11 years on average and for 5 years at minimum. RESULTS: According to Severin's classification, 39 hips (75%) were included in the `satisfactory group', while 13 hips (25%) were `unsatisfactory'. The `unsatisfactory group' consisted of 7 hips showing an impaired secondary ossification center in the acetabular rim, 5 hips with persistent resubluxation after weaning the orthosis, and one hip showing severe coxa magna. Additional bony procedures for the underdeveloped acetabuum and/or proximal femur were required in 12 hips, except for one showing severe coxa magna. CONCLUSION: The radiological outcome of DDH in children in whom the treatment was delayed until 6 to 24 months old was satisfactory in 39 hips (75%). Unsatisfactory hips required additional bony procedures, which we expect will improve the final outcome.