Sequentially Annealed Highly Cross-linked Polyethylene Reduced In Vivo Wear Particle Generation In TKA

Introduction: Polyethylene wear particles induce macrophages to release cytokines, which can lead to osteolysis and aseptic loosening of total joint prostheses. The generation of polyethylene wear particles is one of the most important factors that affect the midterm and long-term clinical results associated with total knee arthroplasty (TKA). Therefore, to achieve better long-term results for patients who have higher activity levels, modifications of materials and design have been developed to reduce polyethylene wear after TKA. Sequentially annealed highly cross-linked polyethylene was expected to reduce the polyethylene particle generation comparing to conventional polyethylene. In vitro studies showed that sequentially annealed highly cross-linked polyethylene generated less but smaller wear particles comparing to conventional polyethylene [1]. Smaller wear particles have higher biological activity, and is suspected to higher probability of osteolysis. Therefore, in vivo effect of annealed highly cross linked polyethylene on wear particle generation is still controversial. However, there has been no report on in vivo wear of sequentially annealed highly cross-linked polyethylene. Our hypothesis was that sequentially annealed highly cross-linked polyethylene reduced the generation of polyethylene wear particles in vivo. The aim of this study is to compare in vivo polyethylene wear particle generation between sequentially annealed highly cross-linked polyethylene and conventional polyethylene.