The specific aim of this proposed study is to conduct a prospective RSA clinical study at Massachusetts General Hospital involving 50 patients receiving primary total hip replacements. All patients will receive the vitamin E treated polyethylene acetabular inserts. Short-term femoral head penetration and long-term steady state wear of the polyethylene will be measured using both RSA and Martell analysis techniques. Stability of the acetabular and femoral components will be measured in all patients using RSA analysis. The stability of the cemented femoral stems will be compared to the stability of the cementless femoral components as well as to historic data in the literature. In addition, all patients will complete a self-administered questionnaire to assess the clinical outcome of the surgery and patient satisfaction.