<qa>  What is the BMD measurement of the proximal femur?3. DXA analysis of the changes in BMD of the periprosthetic Gruen zones will be used to evaluate the adaptive bone remodeling after the implantation of the two different stems. DXA analysis will be performed preoperatively of the hip and proximal tibia as baseline, then again within the first postoperative week and subsequently at 3 months, 6 months, 1 year, 2 years and 5 years. The precision of the BMD measurements of the proximal femur will be estimated from double measurements of patients n12 included in the study. 