Surface damage and wear in fixed, modular tibial inserts: The effects of conformity and constraint

Abstract

The degree of conformity and constraint are thought to play an important role in the severity of wear damage of the polyethylene insert of total knee replacement (TKR). Wear is thought to diminish as a function of increasing conformity and hence increased surface areas and thus diminished contact stresses. However, a study of retrieved polyethylene components of less conforming CR prostheses (MG2) and more conforming PS and CCK devices (IBII) showed more severe wear damage (delamination and pitting) on the articulating surfaces of the more conforming design. In addition, the IB2 post showed substantial wear-related damage, implicating it as an important source of particulate debris. Wear in TKR is a complex phenomenon influenced by many variables beyond the simple relationship between conformity and surface area. © 2005 Springer Medizin Verlag Heidelberg.