Original cementless femoral stem for dysplastic hip: clinical results of HPF stem

We designed and developed the original cementless femoral stem (HPF) adapted to femurs of developmental dysplasia of the hip (DDH). Twenty-three arthroplasties using HPF were performed in 22 cases. The average age at the operation was 48.4 years. The average follow-up period was 6 years and 10 months. The average Harris Hip Score improved from 46.3 points preoperatively to 93.4 points postoperatively. All stems were classified as bone-ingrown or stable fibrous fixation. Clinically and radiologically excellent results proved the design concept of the HPF realized good fixation in the proximal femur with deformities of DDH. The surface treatment worked well for biological fixation even in clinically difficult cases with poor bone quality and/or complicated deformity of the femur of DDH.