CONTACT AREA AS A CRITICAL DETERMINANT IN THE TRIBOLOGY OF METAL-ON-POLYETHYLENE TOTAL JOINT ARTHROPLASTY

摘要

The effects of contact area and contact stress on friction and wear of polyethylene-metal articulation were evaluated using a bi-directional pin-on-disk apparatus. A doubling of the contact area under fixed loading conditions led to a 50% increase in the coefficient of friction and a doubling of the wear rate. There appeared to be a relationship between the increase in wear rate and the increase in the coefficient of friction. A model was developed to explain the mechanism by which engagement of asperities results in the increasing wear rate with increasing contact area despite the decreased stress.