Effects of fusion defects on the wear of ultra high molecular weight polyethylene components use in artificial knee joints

摘要

In the artificial joint, ultra high molecular weight polyethylene (UHMWPE; PE) has been usually employed as a buffer because of high wear resistance and biocompatibility and so on. Life span of the joints are usually controlled by wear resistance of the UHMWPE(PE). It is said that life span in total knee arthroplasty (TKA) is about for 10-20 years, depending on the circumstances. If some trouble such mechanical damage of PE as wear occurred, the life span would be reduced. The wear in TKA appears to be plowing, abrasion by hard asperities of counter face, delamination wear by fatigue of repeated stress on surface, and fracture by crack propagation and so on. In molding of PE, fusion effects in the bulk material has been cited as a major factor affecting the wear in vivo, which could be observed in retrieved PE tibial inserts. The purpose of this study is to examine the effect of fusion defect on wear of PE.