Investigation of Mechanical Problems in the Application of Acetabulum Cups for Hip-Prosthesis

An acetabula-cup is the counterpart of an endoprosthesis and is mounted in the pelvis. There are different designs of such cups. The difference is given only by the kind of applying the forces for mounting the cup (like a screw) in the pelvis. In the realization the forces are applied in 4 notches at the upper border of the cup, whereas in the second case the mounting forces affect 3 cuts in the bottom-plate of the cup. In both cases the mounting stresses may lead to plastic deformations of the contact area. The question is, which solution influences the lifetime prediction more.