Lewis G
Department of Mechanical Engineering, The University of Memphis, TN 38152-3180, USA.
Biomaterials. 2001 Feb;22(4):371-401. doi: 10.1016/s0142-9612(00)00195-2.
Substantially reducing the rate of generation of wear particles at the surfaces of ultra-high-molecular-weight polyethylene (UHMWPE) orthopedic implant bearing components, in vivo, is widely regarded as one of the most formidable challenges in modern arthroplasty. In the light of this, much research attention has been paid to the myriad of endogenous and exogenous factors that have been postulated to affect this wear rate, one such factor being the polymer itself. In recent years, there has been a resurgence of interest in crosslinking the polymer as a way of improving its properties that are considered relevant to its use for fabricating bearing components. Such properties include wear resistance, fatigue life, and fatigue crack propagation rate. Although a large volume of literature exists on the topic on the impact of crosslinking on the properties of UHMWPE, no critical appraisal of this literature has been published. This is one of the goals of the present article, which emphasizes three aspects. The first is the trade-off between improvement in wear resistance and depreciation in other mechanical and physical properties. The second aspect is the presentation of a method of estimating the optimal value of a crosslinking process variable (such as dose in radiation-induced crosslinking) that takes into account this trade-off. The third aspect is the description of a collection of under- and unexplored research areas in the field of crosslinked UHMWPE, such as the role of starting resin on the properties of the crosslinked polymer, and the in vitro evaluation of the wear rate of crosslinked tibial inserts and other bearing components that, in vivo, are subjected to nearly unidirectional motion.
在体内大幅降低超高分子量聚乙烯（UHMWPE）骨科植入物承重部件表面磨损颗粒的产生率，被广泛认为是现代关节置换术中最艰巨的挑战之一。鉴于此，许多研究关注了众多被假定会影响这种磨损率的内源性和外源性因素，其中一个因素就是聚合物本身。近年来，人们对交联聚合物重新产生了兴趣，将其作为一种改善聚合物性能的方法，这些性能被认为与其用于制造承重部件相关。这些性能包括耐磨性、疲劳寿命和疲劳裂纹扩展速率。尽管关于交联对UHMWPE性能影响的主题已有大量文献，但尚未发表对该文献的批判性评估。这是本文的目标之一，本文强调三个方面。第一个方面是耐磨性的提高与其他机械和物理性能的降低之间的权衡。第二个方面是提出一种估计交联过程变量（如辐射诱导交联中的剂量）最佳值的方法，该方法考虑了这种权衡。第三个方面是描述交联UHMWPE领域中一系列未充分研究和未探索的研究领域，例如起始树脂对交联聚合物性能的作用，以及对体内经历几乎单向运动的交联胫骨插入物和其他承重部件的磨损率进行体外评估。
