Structural bone grafting in arthroplasty for congenital hip dysplasia: 35 hips followed for 5-10 years.

We assessed 35 hip arthroplasties in 30 patients with an average follow-up of 7 years. All patients suffered from secondary osteoarthrosis due to congenital dysplasia. The mean age at the time of surgery was 54 (19-77) years. Part of the femoral head used as a graft was fixed to the superolateral region of the acetabulum. A 100% bone coverage of the acetabular component was achieved initially. The mean support by the graft was 34%. The graft size, measured in the AP view, decreased on average 29% after 7 years. The resorption caused a reduction in cup coverage to 94%. There was no correlation between the clinical outcome and the graft size. Graft resorption occurred in the horizontal and vertical axes, but hardly affected the contact region with the iliac bone. Radiolucent lines according to DeLee were found in zone I in 4, zone II in 6 and zone III in 7 cases. The Harris Hip Score improved from 37-85 points. 1 revision was necessary 7 months postoperatively after cup dislocation.