Effect of Femoral Stem Design om Cement Mantle Failure

股骨柄设计对水泥套失效的影响

基本信息

批准号：
7103403
负责人：
AMOS RACE
金额：
$ 7.6万
依托单位：
UPSTATE MEDICAL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-09-13 至 2008-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7103403
关键词：
bioengineering /biomedical engineering biomaterial compatibility biomaterial development /preparation biomaterial evaluation biomechanics clinical research femur hip prosthesis mechanical stress medical implant science

项目摘要

DESCRIPTION (provided by applicant): The goals of this project are to improve understanding of how femoral stem design effects cement mantle failure in total hip replacements (THR) and to validate a pre-clinical test for cemented femoral stems. THR has been a very common procedure for some time. Cemented femoral components, which rely on Polymethylmethacrylate (PMMA) for fixation of the stem within the bone, account for about half of the THR done in the USA. Worldwide, cemented stems are used far more commonly. Despite the widespread and ongoing use of PMMA cement for femoral stem fixation, the influence of stem design on cement mantle failure is poorly understood. Many 'improved' designs of cemented femoral stem have been introduced in recent years but with mixed clinical results. That novel stem designs have caused such surprises is due, in part, to the lack of an in vitro analogue that can accurately model the medium to long-term response to cyclic loading of the stem/cement/femur system. The goal of this project is to develop and validate such an in vitro analogue. A physical model is proposed by which the medium to long-term fatigue response of a PMMA cement mantle can be simulated in cadaveric tissue. The key feature of the model is formulation of cement with degraded fatigue fracture properties (sub-cement) such that long-term fatigue tests can be shortened by two orders of magnitude. Specific Aims: 1 To formulate sub-cement, which will be similar to conventional PMMA bone cements in terms of modulus, yield stress, and viscosity but will be substantially more susceptible to fatigue crack propagation. 2 To demonstrate that cemented femoral stems with lower and higher risks of medium to long term aseptic loosening can be differentiated by analysis of in vitro fatigue damage and stem/femur micro-motions in a sub-cement based stem/cement/femur construct. 3 To demonstrate that damage accumulation patterns in sub-cement based stem/cement/femur constructs correlate with patterns found in post-mortem retrievals. Should these aims be met, the proposed model will be of great use in pre-clinical testing of novel cemented stem designs.

描述（由申请人提供）：该项目的目标是提高对股骨柄设计如何影响全髋关节置换术 (THR) 中骨水泥套失效的理解，并验证骨水泥股骨柄的临床前测试。一段时间以来，THR 一直是一种非常常见的手术。骨水泥股骨组件依靠聚甲基丙烯酸甲酯 (PMMA) 将股骨柄固定在骨内，约占美国 THR 的一半。在世界范围内，骨水泥柄的使用更为普遍。尽管PMMA水泥广泛且持续地用于股骨柄固定，但柄设计对水泥套失效的影响却知之甚少。近年来，已经推出了许多“改进”的骨水泥股骨柄设计，但临床结果好坏参半。新颖的股骨柄设计之所以引起如此惊讶，部分原因是缺乏能够准确模拟股骨柄/骨水泥/股骨系统循环负荷的中长期反应的体外类似物。该项目的目标是开发和验证这种体外类似物。提出了一种物理模型，可以在尸体组织中模拟 PMMA 水泥罩的中长期疲劳响应。该模型的主要特点是配制疲劳断裂性能降低的水泥（子水泥），从而可以将长期疲劳测试时间缩短两个数量级。具体目标： 1 配制底层水泥，其在模量、屈服应力和粘度方面与传统 PMMA 骨水泥相似，但更容易受到疲劳裂纹扩展的影响。 2 证明通过分析基于次水泥的股骨柄/骨水泥/股骨结构中的体外疲劳损伤和股骨柄/股骨微运动，可以区分中长期无菌性松动风险较低和较高的骨水泥股骨柄。 3 证明基于次水泥的干/水泥/股骨结构中的损伤累积模式与死后检索中发现的模式相关。如果这些目标能够实现，所提出的模型将在新型骨水泥柄设计的临床前测试中发挥重要作用。