Knee joint replacement wear resistance

Other studies, conversely, cast doubt on the ultimate viability of carbon-UHMWPE composite usage in hip and knee joint replacement, especially after clinical exposure. After longer-duration pin-on-disc studies using 25% graphite powder-filled UHMWPE, Rostoker and Galante reported that the short-term improvement in wear resistance appeared to be lost [17]. Sclippa and Piekarski... 

Abrasive wear of polymers has two components material can be removed by the rasping action of a countersurface or it can be sheared off viscoelastically by a countersurface to which it adheres. The precise balance of mechanisms depends on the characteristics of the counterface and the conditions under which the abrasion takes place. Many polymers exhibit excellent wear resistance, which in combination with their low coefficients of friction suit them for applications where lubrication is either impossible or undesirable. We use wear resistant polymers in such diverse applications as bushings in business machines, pump seals, and replacement hip and knee joints. 

---