BACKGROUND: The purpose of this study was to analyze whether hips treated for developmental dysplasia of the hip (DDH) during infancy, which were clinically and radiologically fully normalized by walking age, may become dysplastic again during later growth. MATERIALS AND METHODS: A total of 150 patients were randomly selected out of a collective of 386 patients treated for DDH at the Department of Orthopaedics at the University of Zurich between 1993 and 2004. Treatment was started at birth and continued for 6 months. All patients had clinically and radiographically normal hips by walking age. The patients did not suffer from other diseases, in particular, neurological or neuromuscular diseases. RESULTS: We detected four female subjects among the 150 patients who had been successfully treated for DDH, who had developed dysplastic hips in early adolescence, necessitating acetabular surgery. CONCLUSION: The successful treatment of DDH in infancy does not ensure normal hip development; therefore, follow up into maturity may be recommended. LEVEL OF EVIDENCE: Level IV
