<qa>  What is the expected prospective decrease in BMD of the proximal femurBone remodeling DXA. The expected prospective decrease in BMD of the proximal femur after insertion of an uncemented THA is most pronounced in Gruen zones 1 and 7 with decreases of respectively 13-21 and 10-31. In this study investigator intend to measure a significant difference MIREDIF in percentage changes in BMD between the two groups of 7.5. Even though several studies evaluating prospective changes in BMD around a femoral stem have been published, investigator did not find a study with precise information of the SD of the percentages in BMD. Thus, investigator estimated a SD of the changes in BMD of 8 that could be used for calculating sample size in our study. 