Pérez M A, García-Aznar J M, Doblaré M
Group of Structural Mechanics and Materials Modelling, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Betancourt Building, c/ María de Luna, 50018 Zaragoza, Spain.
Ann Biomed Eng. 2009 Mar;37(3):454-66. doi: 10.1007/s10439-008-9616-7. Epub 2008 Dec 16.
Implant loosening is one of the most important modes of failure of cemented total hip replacement. It may be related to the cement strength, cement-prosthesis interface, cement-bone interface, surgical technique, or stem design. The main purpose of this study is to investigate the effect of bone-cement interface mechanical properties on cement degradation. The computational methodology proposed herein combines a previously developed bone-cement interface damage model and an accumulative damage model for bulk cement. This has been applied to a finite element model of an Exeter cemented hip implant. A higher strength of the bone-cement interface due to a higher amount of interdigitated bone results in faster cement deterioration. Over time, damage both at the bone-cement interface and in the cement mantle worsens. Also, a larger debonded area was predicted proximally, as observed in clinical practice. We conclude that the computational model proposed herein allows a realistic simulation of the bone-cement interface debonding and cement degradation, being a useful tool in the design of this kind of medical devices.
植入物松动是骨水泥型全髋关节置换术最重要的失败模式之一。它可能与骨水泥强度、骨水泥-假体界面、骨水泥-骨界面、手术技术或柄部设计有关。本研究的主要目的是研究骨水泥界面力学性能对骨水泥降解的影响。本文提出的计算方法结合了先前开发的骨水泥界面损伤模型和整体骨水泥累积损伤模型。这已应用于埃克塞特骨水泥型髋关节植入物的有限元模型。由于相互交错的骨量增加导致骨水泥界面强度更高，从而使骨水泥更快地恶化。随着时间的推移，骨水泥界面和骨水泥壳层的损伤都会加剧。此外，如临床实践中所观察到的，预计近端会出现更大的脱粘区域。我们得出结论，本文提出的计算模型能够对骨水泥界面脱粘和骨水泥降解进行逼真的模拟，是设计这类医疗器械的有用工具。
