<qa>  What is the femoral neck and upper end of the femur?From our experience with the aforementioned short prosthesis, the investigators have joined with Biomechanical Institute, Royal National Orthopaedic Hospital, Stanmore, London and firm Biomet developed a modern design of the above. This is a short prosthesis that is anchored in the femoral neck and the upper end of the femur metaphysis. Prosthesis made of titanium with a porous surface Bonemaster . The prosthesis is anchored during surgery by pressure-fit press-fit and in a few weeks the bone grows into the prosthesis. 