Abstract: | To assure the quality of hip joint endoprosthesis stems, comparative investigations are made for the first time on marketable prostheses of different producers to determine fatigue and corrosion fatigue strength under long time service conditions. The results show that even for these remarkable corrosion resistant materials (cast CoCrMo-and wrought CoNiCrMo-alloys) under test conditions which are relevant for practice there exists no real fatigue strength, but only a corrosion fatigue loadability for finite life time. The fatigue loadability obtained in air will be reduced remarkably by the simultaneous effect of the physiological NaCl-solution. Recommendations for an effective system of quality assurance are given. |