Engineers, biologists and surgeons face a special task when they design procedures, components and systems to replace tissues damaged beyond any limits, caused by disease or trauma. It has been proven that titanium and its alloys have an excellent biocompatibility, that's why many studies have been made on them, in order to enhance their biomedical applicability. In this paper, the wear behavior of HEMA was analyzed, for use as a cartilage substitute, in experimental models in vivo for testing under conditions very close to reality for two new materials, Til2Mo and Ti25Nb25Ta alloys.