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.

无菌松动仍然是髋关节置换术的问题。 在胶结的总髋关节置换术中，机械诱导的松动最常见于干胶或水泥骨界面。 通过缺乏对导致松动的实际机械条件的理解以及依赖于茎设计，茎表面条件和胶结技术的故障过程的多因素性质，我们缺乏了解实际机械条件的理解，从而改善了胶结的总髋关节置换的结果。在这项工作中，描述了一项研究计划以研究：（1）茎颈和水泥骨接口失败的特定机械疲劳条件； （2）茎设计，茎表面和胶结过程的方式有助于界面和散装水泥的疲劳失败过程； （3）这三个设计因素在影响疲劳失败过程时的相互作用。 这项研究的最终目标是定义设计指南，以降低由于植入物松动而导致的髋关节置换率的修订率。正是这项工作的假设使茎设计，茎表面和胶结条件都会影响植入物系统的整体失败（松动）。在拟议的研究中，将使用基于断裂力学的方法来表征干螺骨和水泥骨接口的疲劳行为和失败。 界面响应的模型将从实验和理论方法的组合开发出来，这些模型将通过比较预测的与模型开发不同的实验的预测结果进行比较。 在每个设计条件下，将使用具有侵略性的楼梯攀爬载荷方向进行胶结茎构建体的环状疲劳实验。 这些实验将直接通过使用23个阶乘实验设计直接检验上述假设。 最后，将执行八种设计案例中每一个的完全3-D疲劳模型，以阐明实验中发现的故障机制。合并后，实验和计算方法将提供设计指南，这些指南可能会大大降低由于植入物松动而导致的胶结髋关节置换率的修订率。