ARTIFICIAL HIP JOINTS - A CHALLENGE FOR I DEAS CONCERNING TRIBOLOGY AND DESIGNING

Artificial hip joints are successfully used since two decades. The art ificial joint is set up out of a femoral ball head made of a cobalt ch romium alloy or alumina ceramic. The ball head is mostly articulating against an acetabular cup made of polyethylene (UHMWPE). The polyethyl ene wear debris causes osteolysis. Because of the osteolysis the impla nts will loosen and a revision of the artificial hip joint has to be p erformed. The objective of all R & D projects is to minimize the polye thylene wear. The state-of-the-art is discussed. There are new materia ls and methods that offer oppertunities for new combinations. Possibil ities, limitations and the successes are discussed. The clinical exper ience during the last two decades proved that femoral ball heads made of alumina ceramic could reduce the problems of osteolysis.