ABSTRACT
PURPOSE: The purpose of this study is to evaluate the usefulness of a modular total hip system for combined anteversion in cementless modular total hip arthroplasty. MATERIALS AND METHODS: We performed twenty cementless modular total hip arthroplasty procedures. The patients lay in lateral position and 15degreesinternal rotation of the thigh. The surgeon inserted an acetabular cup component first, followed by a femoral component. He selected an appropriate modular neck component using an intra-operative manual combined anteversion test. All patients underwent post-operative computed tomography. RESULTS: The average measurement of anteversion of the acetabular cup was 15.9+/-2.9degrees and anteversion of the femoral stem was 15.2+/-11.9degrees. Then, the combined anteversion was calculated to 24.0+/-8.2degrees. Significant difference was observed between combined anteversion and theoretical combined anteversion. CONCLUSION: The method using an intra-operative manual combined anteversion test cannot realize the theoretical combined anteversion in cementless modular hip arthroplasty.