INTERFACE FAILURE IN TOTAL JOINT REPLACEMENTS

全关节置换术中的接口故障

• 批准号: 6369915
• 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/6369915
• 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。在骨水泥全髋关节置换术中，机械引起的松动通常始于骨干-骨水泥或骨水泥界面。由于我们缺乏对导致髋关节松动的实际机械条件的了解，以及髋杆设计、髋杆表面条件和骨水泥技术导致的髋关节失效过程的多因素性质，提高骨水泥全髋关节置换术的效果受到了限制。在这项工作中，描述了一项研究计划，以研究：(1)在特定的机械疲劳条件下，茎-水泥和水泥-骨界面失效；(2)管柱设计、管柱表面和固井工艺对界面处和散装水泥中疲劳破坏过程的影响；(3)这三个设计因素对疲劳破坏过程的相互作用。本研究的最终目标是确定设计指南，以减少由于植入物松动而导致的骨水泥髋关节置换术的翻修率。本研究假设假体设计、假体表面和固井条件都会影响假体系统的整体失效（松动）。在拟议的研究中，基于断裂力学的方法将用于表征茎-水泥和水泥-骨界面的疲劳行为和破坏。将结合实验和理论方法开发界面响应模型，并将这些模型通过与用于模型开发的实验不同的预测结果与观察结果的比较来验证。在每个设计条件下，将对胶结杆结构进行剧烈爬楼梯加载的循环疲劳试验。这些实验将通过使用23因子实验设计直接检验上述假设。最后，将对8种设计情况中的每一种进行全三维疲劳模型，以阐明在实验中发现的破坏机制。当实验和计算方法相结合时，将提供设计指南，可以显着降低由于植入物松动而导致的骨水泥髋关节置换术的翻修率。