Improved friction and wear performance in polymeric components of orthopaedic bearings.

改善骨科轴承聚合物部件的摩擦和磨损性能。

• 批准号: RGPIN-2018-06628
• 负责人: Bryant, John
• 金额: $ 6.7万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=759842
• 关键词: Improved; friction; wear; performance; polymeric

Hip and knee replacements are most often designed using specialized components made of metal (cobalt chrome) and plastic (ultrahigh molecular weight polyethylene). These devices are the treatment of choice for severe degenerative joint disease, and they are now being implanted in younger more active patients. As a result, there is an increased need to improve their durability, particularly with respect to wear in the plastic component. Of concern is the phenomenon of osteolysis, in which the bone surrounding an artificial joint reacts to plastic wear particles and dies. Consequently, the implant loosens and needs to be replaced. There have been improvements in the design of polyethylene for use in hips, but this has not been the case for highly stressed joints such as the knee. This project examines a novel way of treating the plastic to reduce wear. It is thought that indentations in the polyethylene surface will entrain joint fluid, thus developing locally pressurized regions that reduce the stress on the plastic itself. In a previous NSERC-funded study, it was discovered that specific patterns of indentations reduce plastic stress and also reduce friction in these systems. However, research in other laboratories has shown that one of the conditions leading to excessive wear is not the continuous motion of walking, but the discontinuous motion of stopping and starting. It is thought that during these episodes, the fluid that lubricates the surfaces seeps out when stopping, thus leaving the plastic unprotected from wear when motion starts again. The objective of this project is to understand this mechanism of wear and to determine whether the initial positive findings of texturing will result in reduced plastic wear during intermittent motion. Samples of plastic will be textured and tested in a device that simulates the stop-start motion. If successful, the texturing process will be evaluated on artificial joints in a wear simulator that produces the same loads and motion that occur in real life.Nearly 25,000 Canadians and 600,000 worldwide are implanted with an artificial knee each year. By improving their durability beyond the 15 years currently expected, researchers hope to provide a growing number of our aging population with a lifetime of activity well past what is now possible.

髋关节和膝关节置换术通常使用由金属（钴铬）和塑料（超高分子量聚乙烯）制成的专门部件进行设计。这些装置是治疗严重退行性关节疾病的首选，它们现在被植入更年轻、更活跃的患者体内。因此，提高其耐久性的需求增加了，特别是在塑料部件的磨损方面。值得关注的是骨溶解现象，在这种现象中，人工关节周围的骨头对塑料磨损颗粒产生反应并死亡。因此，种植体松动，需要更换。用于髋关节的聚乙烯的设计已经有所改进，但对于像膝盖这样的高度受力的关节来说，情况还不是这样。这个项目研究了一种处理塑料以减少磨损的新方法。据认为，聚乙烯表面的压痕将夹带关节流体，从而形成局部加压区域，从而减少塑料本身的应力。在之前nserc资助的一项研究中，研究人员发现，特定的压痕模式可以减少这些系统中的塑性应力，也可以减少摩擦。然而，其他实验室的研究表明，导致过度磨损的条件之一不是行走的连续运动，而是停止和启动的不连续运动。据认为，在这些过程中，润滑表面的液体在停止时渗出，从而使塑料在再次运动时不受磨损。这个项目的目的是了解这种磨损机制，并确定是否最初的积极发现纹理将导致减少间歇性运动期间的塑性磨损。塑料样品将在一个模拟停止-启动运动的设备中进行纹理和测试。如果成功，将在磨损模拟器中对人造关节进行纹理加工，产生与现实生活中相同的负载和运动。每年有近2.5万加拿大人和全世界60万人植入人工膝盖。研究人员希望通过提高它们的耐久性，使其超过目前预期的15年，为越来越多的老龄化人口提供远远超过目前可能的终身活动。