Institute for Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, UK.
Clin Orthop Relat Res. 2010 Jan;468(1):12-8. doi: 10.1007/s11999-009-1033-1. Epub 2009 Aug 11.
Knee arthroplasties in young and active patients place a substantial increase in the lifetime tribological demand and potential for wear-induced osteolysis. Polyethylene materials have advanced in recent years, reducing the potential for oxidative degradation and delamination failure. It is timely to consider tribological design variables and their potential to reduce surface wear and the long-term risk of osteolysis. The influence of reduced cross shear in rotating platform mobile-bearing knee designs and reduced surface wear area in low conforming fixed-bearing knees has been investigated. A reduction in cross shear substantially reduced wear in both multidirectional pin-on-plate studies and in rotating platform mobile-bearing designs in knee simulator studies. A reduction in bearing surface contact area substantially reduced surface wear in multidirectional pin-on-plate simulations and in low conforming fixed-bearing knee designs in knee simulator studies. This offers potential for a paradigm shift in knee design predicated by enhanced mechanical properties of new polymer materials. We describe two distinct low-wearing tribological design solutions: (1) a rotating platform design solution with reduced cross shear provides reduced wear with conformity and intrinsic stability; and (2) a low conformity fixed bearing with reduced surface area, provides reduced wear, but has less intrinsic stability and requires good soft tissue function.
膝关节置换术在年轻且活跃的患者中，会大大增加寿命内的摩擦学需求和磨损诱导性骨溶解的风险。近年来，聚乙烯材料得到了发展，降低了氧化降解和分层失效的可能性。现在正是考虑摩擦学设计变量及其减少表面磨损和长期骨溶解风险的潜力的时候了。已经研究了旋转平台活动衬垫膝关节设计中减少横向剪切和低顺应性固定衬垫膝关节中减少表面磨损面积的影响。在多向销盘试验和膝关节模拟器研究中的旋转平台活动衬垫设计中，横向剪切的减少大大减少了磨损。在多向销盘模拟试验和膝关节模拟器研究中的低顺应性固定衬垫膝关节设计中，减少轴承表面接触面积大大减少了表面磨损。这为基于新型聚合物材料增强的机械性能的膝关节设计提供了一种范式转变的潜力。我们描述了两种不同的低磨损摩擦学设计解决方案：（1）具有减少横向剪切的旋转平台设计解决方案提供了具有一致性和固有稳定性的减少磨损；（2）具有减少表面面积的低顺应性固定轴承，提供了减少磨损，但固有稳定性较差，需要良好的软组织功能。
