Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip.

Abstract

Total joint replacement in patients suffering from developmental dysplasia of the hip poses specific technical difficulties due to insufficient bone stock at the site of the original and secondary acetabulum and a narrow, cranially displaced proximal femur. Twelve hips with severe congenital dislocation (4 Crowe type II, 5 type III, 3 type IV) were treated with cementless, porous structured total hip replacement. The cup was implanted at the anatomic height, a femoral segment was resected below the minor trochanter to reduce the femoral component in all cases. One femoral component was exchanged for a longer stem after 2 months due to insufficient fit and fill. After a mean follow-up of 5.1 years, there were no further revisions or radiographic signs of loosening. No cup was revised or loose radiographically. Harris hip score (mean) improved from 36 to 82 points, mean leg length discrepancy was reduced from 5.4 to 1.3 cm. The cementless technique described is useful in cases of severe congenital dislocation of the hip when the cup is implanted at the anatomic level, and implant reduction is not possible despite thorough soft-tissue release or not advisable because of excessive limb lengthening. A reconstruction of the original joint center and good mid-term results are demonstrated.