Artificial joint, in particular an endoprothesis for the human knee joint, consisting of at least two joint parts moving with respect to each other, a joint head and a joint base, with toroidal joint surfaces, that have function surfaces with differing circular intersection contours in mutually perpendicular...http://www.google.de/patents/US5556432?utm_source=gb-gplus-sharePatent US5556432 - Artificial joint
