Development and wear testing of bi-material bearing surfaces for hip arthroplasty

描述(申请人提供)：髋关节置换手术是一种非常有效和成功的治疗退行性关节疾病的方法。然而，翻修手术约占美国髋关节植入手术的13%，每年花费30亿美元，显著增加了患者的发病率和并发症风险。全髋关节置换术(THA)轴承表面的磨损和/或失效是设备失效的主要原因之一，直接原因是轴承关节不良或磨损碎片的有害影响。这项拟议的工作将开发和测试一种新的轴承，用于临时避震装置。与最先进的轴承设计方法相比，这种新的方法将减少轴承表面的损坏和磨损。如果这一项目成功，THA中轴承表面的基本设计每年可能会为数十万患者而改变。预计这一产品设计将减轻美国人工关节翻修的负担。对失败的整形外科设备的实验室研究使开发团队了解到当前行业设计的缺点。对临床检索的独立研究提供了令人信服的证据，表明硬性髋关节轴承故障是由意想不到的动态头缘接触引起的。临床上会发生磨损、疲劳失效和表面损伤。因此，拟议项目的目标是为人工髋关节开发新的轴承表面，为患者提供非常高的硬-硬轴承副的耐磨性，并在最需要的地方提供聚合物(如超高分子质量聚乙烯)的韧性和抗冲击性。拟议的工作将通过新轴承的进一步开发、制造、测试和建模来确定可行性。该研究计划将建立可测量和可重复的方案，用于测试建议表面的弹性和耐磨性，将在反映活体真实条件的高接触应力载荷下进行验证，将建立新磨损界面的概念证明，并将开发轴承界面机械行为的数值模型。需要回答的问题包括模拟环境的有效性、建议的材料界面的弹性以及在建议的轴承设计中预测损伤的能力。

DESCRIPTION (provided by applicant): Hip replacement surgery is a tremendously effective and successful treatment for patients suffering from degenerative joint disease. However, revision surgery accounts for about 13% of hip implant surgeries in the U.S., costing $3 billion annually and presenting significantly increased morbidity and risk of complication for patients. Wear and/or failure of total hip arthroplasty (THA) bearing surfaces is one of the leading causes of device failure, either directly because of poor bearing articulation or through the detrimental effects of wear debris. The proposed work will develop and test a new bearing to be employed in a THA device. This novel approach will reduce bearing surface damage and wear when compared to state of the art approaches in bearing design. If this project is successful, the fundamental design of the bearing surface in THA could change for hundreds of thousands of patients every year. It is expected that this product design will reduce the United States arthroplasty revision burden. Laboratory research in failed orthopedic devices has informed the development team's understanding of the shortcomings of current industry designs. Independent studies of clinical retrievals provide compelling evidence that hard-on-hard hip bearing failure is driven by unanticipated dynamic head-to-rim contact. Wear, fatigue failure, and surface damage occur clinically. Thus, the goal of the proposed project is to develop new bearing surfaces for artificial hips that offer patients the very high wear resistance of hard-on-hard bearing couples and also offer the toughness and impact resistance of polymers such as ultra-high molecular weight polyethylene where most needed. The proposed work will establish feasibility through further development, manufacture, testing and modeling of the new bearing. The research plan will establish measureable and repeatable protocols for testing resilience and wear resistance of proposed surfaces, will proceed to validation in high contact stress loading that reflects true in vivo conditions, will establish proof of concept of new wear interfaces, and will develop a numerical model of the mechanical behavior of the bearing interface. Questions to be answered include validity of the simulation environment, resilience of the proposed material interface, and the ability to predict damage in the proposed bearing designs.