<qa>  What is the purpose of this study?The purpose of this study is to compare the performance of 4 designs of the DePuy Ultima LX hip stem in the treatment of patients with hip joint disease requiring a total hip replacement. Patients who enter the study will be randomly allocated to one of the 4 designs of the DePuy Ultima LX hip stem and will be evaluated at regular intervals following hip surgery using patient, clinical and x-ray assessments. 