<qa>  What is the bone mass at the femoral neck and the very top end of theIn Orthopaedic Surgery, Region Nordjylland, one has in the period 1999 to 2003 33 such prostheses implanted at clinics in Farsø and Frederikshavn and achieved good results apart from pain similar to the above anchoring screws. At follow-up of these prostheses, using DEXA scans, the investigators have shown that prosthesis, bone-saving, since bone mass at the femoral neck and the very top end of the femur bone is preserved. 