wear of articulating surface of joint replacement

Hi everyone out there...

Now i'm working on biomechanics research project which deals with the articulating surface of joint replacement, where one of the main problem were the wear of sliding contact (i.e., metal on polymer,metal on metal or polymer on ceramics).wear debris or particles generated from this articulating surface can causes the damage of the bone cell around the joint replacement.My question are;

Is it out there existing fortran subroutine codes which simulate the wear equation of two contact surfaces?if no, can somebody guide me on how to develop this governing equation..

Please correct me if i'm get wrong.Thank you...