Computational wear simulation using ratated femoral head on acetabular cup applicable to hard-on hard hip joint replacement

Metal-on-metal (MOM) bearings are currently accepted as alternative to polymer-on-metal (POM) articulation for hip implants to reduce wear debris induced osteolysis. MOM total hip replacement was introduced in the late 30’s by Philip Wiles (Dowson, 2004). Due to disappointing result, McKee employed cast cobalt alloy in the 1960s. Analysis of some retrieved firstgeneration MOM prostheses demonstrated that the volumetric and linear wear rates of MOM were often far lower than POM. The linear wear rate is at least 20 times less than POM in the range of 2-20 µm per year and the volumetric wear rate is at least 100 times less than POM in the range of 0.22 to 22.36 mm 3 per year (Sieber et al., 1999). However the success of POM with better clinical result, led the discontinuation of the use of MOM prostheses even there were a few of the prostheses survived for over 30 years.