Total hip arthroplasty for Crowe type IV developmental hip dysplasia: a long-term follow-up study.

A consecutive series of 118 total hip arthroplasties was performed for Crowe type IV developmental hip dysplasia in 89 patients. The mean age of the patients was 52 years. All procedures were carried out through a transtrochanteric approach by the same surgeon. In all cases, the acetabular component was placed at the level of the true acetabulum. The mean lengthening of the operated limb was 3.8 cm. The average follow-up of the whole series was 12.8 years. At the last follow-up evaluation, 29 patients (35 hips) had died or were lost to follow-up at a mean of 11 years. Sixty patients (83 hips) were still alive at a mean follow-up of 16 years. At the time of last follow-up, the mean Merle d'Aubigné hip score was 17.4 compared with 10.6 preoperatively. The survival rate, with revision for any reason as the endpoint, was 78% at 20-year follow-up.