INTERFACE FAILURE IN TOTAL JOINT REPLACEMENTS

全关节置换术中的接口故障

• 批准号: 6511728
• 负责人: KENNETH A. MANN
• 金额: $ 21.66万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6511728
• 关键词: arthroplasty; biomaterial development /preparation; biomaterial evaluation; biomaterial interface interaction; biomechanics; hip prosthesis; mechanical stress; medical implant science; medical rehabilitation related tag

Aseptic loosening continues to be a problem with total hip replacements. In cemented total hip replacement, mechanically induced loosening most often initiates at the stem-cement or cement-bone interface. Improving the outcomes of cemented total hip replacement is limited by our lack of understanding of the actual mechanical conditions that cause loosening, and the multifactorial nature of the failure process that depends on stem design, stem surface conditions, and cementing technique. In this work, a research program is described to investigate: (1) the specific mechanical fatigue conditions under which the stem-cement and cement-bone interfaces fail; (2) the manner in which stem design, stem surface, and cementing process contribute to the fatigue failure process at the interfaces and in the bulk cement; and (3) the interactions between these three design factors in affecting the fatigue failure process. The end goal of this research is to define design guidelines that will reduce the revision rates of cemented hip replacements due to implant loosening. It is the hypothesis of this work that stem design, stem surface, and cementing conditions can each effect the overall failure (loosening) of the implant system. In the proposed research, fracture mechanics-based approaches will be used to characterized the fatigue behavior and failure of the stem-cement and cement-bone interfaces. Models for interface response will be developed from a combination of experimental and theoretical methods, and these models will be verified by comparison of predicted to observed results for experiments that are different than those used for model development. Cyclic fatigue experiments of cemented stem construct will be performed with an aggressive stair climbing loading regime for each of the design conditions. These experiments will directly test the hypothesis stated above through use of a 23 factorial experimental design. Finally, fully 3-D fatigue models of each of the eight design cases will be performed to elucidate the failure mechanisms found in the experiments. When combined, the experimental and computational approaches will provide design guidelines that could significantly reduce revision rates of cemented hip replacements due to implant loosening.

无菌性松动仍然是全髋关节置换术的一个问题。在骨水泥型全髋关节置换术中，机械诱导的松动最常始于柄-骨水泥或骨水泥-骨界面。由于我们缺乏对导致松动的实际力学条件的了解，以及取决于假体设计、假体表面状况和粘固技术的失败过程的多因素性质，限制了骨水泥全髋关节置换术的疗效。在这项工作中，描述了一个研究计划，以调查：(1)杆-水泥和水泥-骨界面失效的特定机械疲劳条件；(2)杆设计、杆表面和胶结过程对界面和散装水泥中疲劳破坏过程的影响方式；以及(3)这三个设计因素之间的交互作用对疲劳破坏过程的影响。这项研究的最终目标是确定设计指南，以降低由于假体松动而导致的骨水泥髋关节置换术的翻修率。这项工作的假设是，支架设计、支架表面和粘接条件都会影响植入系统的整体失败(松动)。在拟议的研究中，将使用基于断裂力学的方法来表征茎-水泥和水泥-骨界面的疲劳行为和破坏。界面响应模型将由实验和理论方法相结合来开发，这些模型将通过将不同于模型开发的实验的预测结果与观测结果进行比较来验证这些模型。在每种设计条件下，水泥杆结构的循环疲劳试验将在积极的爬楼梯载荷状态下进行。这些实验将通过使用23因子实验设计来直接检验上述假设。最后，将对八个设计案例的每个案例进行全三维疲劳模型，以阐明在实验中发现的失效机制。当实验和计算方法结合在一起时，将提供设计指南，可以显著降低由于假体松动而导致的骨水泥髋关节置换术的翻修率。