We have documented the long term radiological outcome of developmental dysplasia of the hips (DDH) complicated by avascular necrosis (AVN). We have also assessed whether a policy of prolonged post-reduction containment has improved the results. Radiographs of patients with a minimum of 10 years followup wer assessed, and AVN diagnosed accordingly to Crerand and O’Brien’s criteria. Outcome grading was assessed by Severin’s criteria, and head sphericity using Mose’s rings.

We identified 35 hips (35 patients) who had developed AVN. Twenty hips had a medial pattern of deformity, and 15 had a valgus pattern. Fifteen hips were Severin grade III, 13 were grade IV, and 3 were grade V. Twenty four patients had more than 6 mm discrepancy in the head of sphericity. Six patients were reviewed clinically: 4 of 5 patients who were < 24 years old have hip symptoms, and the other patient (age 41) has osteoarthritis.

These results confirm that AVN is a serious complication with a poor longterm outcome, and that our prolonged containment treatment does not produce better results than those published on patients with shorter containment periods.