Taylor Mark, Prendergast Patrick J
Medical Device Research Institute, School of Computer Science, Engineering and Mathematics, Flinders University, Adelaide, Australia.
Trinity Centre for Bioengineering, University of Dublin, Trinity College, Dublin, Ireland.
J Biomech. 2015 Mar 18;48(5):767-78. doi: 10.1016/j.jbiomech.2014.12.019. Epub 2014 Dec 18.
Finite element has been used for more than four decades to study and evaluate the mechanical behaviour total joint replacements. In Huiskes seminal paper "Failed innovation in total hip replacement: diagnosis and proposals for a cure", finite element modelling was one of the potential cures to avoid poorly performing designs reaching the market place. The size and sophistication of models has increased significantly since that paper and a range of techniques are available from predicting the initial mechanical environment through to advanced adaptive simulations including bone adaptation, tissue differentiation, damage accumulation and wear. However, are we any closer to FE becoming an effective screening tool for new devices? This review contains a critical analysis of currently available finite element modelling techniques including (i) development of the basic model, the application of appropriate material properties, loading and boundary conditions, (ii) describing the initial mechanical environment of the bone-implant system, (iii) capturing the time dependent behaviour in adaptive simulations, (iv) the design and implementation of computer based experiments and (v) determining suitable performance metrics. The development of the underlying tools and techniques appears to have plateaued and further advances appear to be limited either by a lack of data to populate the models or the need to better understand the fundamentals of the mechanical and biological processes. There has been progress in the design of computer based experiments. Historically, FE has been used in a similar way to in vitro tests, by running only a limited set of analyses, typically of a single bone segment or joint under idealised conditions. The power of finite element is the ability to run multiple simulations and explore the performance of a device under a variety of conditions. There has been increasing usage of design of experiments, probabilistic techniques and more recently population based modelling to account for patient and surgical variability. In order to have effective screening methods, we need to continue to develop these approaches to examine the behaviour and performance of total joint replacements and benchmark them for devices with known clinical performance. Finite element will increasingly be used in the design, development and pre-clinical testing of total joint replacements. However, simulations must include holistic, closely corroborated, multi-domain analyses which account for real world variability.
四十多年来，有限元法一直被用于研究和评估全关节置换的力学行为。在Huiskes的开创性论文《全髋关节置换的失败创新：诊断与治疗建议》中，有限元建模是避免性能不佳的设计进入市场的潜在治疗方法之一。自该论文发表以来，模型的规模和复杂性显著增加，并且有一系列技术可用于预测初始力学环境，直至进行包括骨适应、组织分化、损伤积累和磨损的先进自适应模拟。然而，我们距离有限元法成为一种有效的新设备筛选工具更近了吗？这篇综述对当前可用的有限元建模技术进行了批判性分析，包括：（i）基本模型的开发、适当材料属性的应用、载荷和边界条件；（ii）描述骨-植入物系统的初始力学环境；（iii）在自适应模拟中捕捉随时间变化的行为；（iv）基于计算机的实验的设计与实施；以及（v）确定合适的性能指标。基础工具和技术的发展似乎已趋于平稳，进一步的进展似乎受到模型数据不足或需要更好地理解力学和生物学过程基本原理的限制。基于计算机的实验设计取得了进展。从历史上看，有限元法的使用方式与体外测试类似，仅进行有限的一组分析，通常是在理想化条件下对单个骨段或关节进行分析。有限元法的强大之处在于能够运行多次模拟，并探索设备在各种条件下的性能。实验设计、概率技术以及最近基于人群的建模越来越多地被用于考虑患者和手术的变异性。为了拥有有效的筛选方法，我们需要继续开发这些方法，以检查全关节置换的行为和性能，并将其与具有已知临床性能的设备进行基准对比。有限元法将越来越多地用于全关节置换的设计、开发和临床前测试。然而，模拟必须包括全面、紧密佐证的多领域分析，以考虑现实世界中的变异性。
