Computationally efficient modelling of hip replacement separation due to small mismatches in component centres of rotation.
Computationally efficient modelling of hip replacement separation due to small mismatches in component centres of rotation.
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DOI：
10.1016/j.jbiomech.2019.07.040
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发表时间：
2019-10
影响因子：
2.4
通讯作者：
L. Etchels;Lin Wang;M. Al-Hajjar;S. Williams;J. Thompson;G. Isaac;R. Wilcox;A. Jones
中科院分区：
文献类型：
--
作者：
L. Etchels;Lin Wang;M. Al-Hajjar;S. Williams;J. Thompson;G. Isaac;R. Wilcox;A. Jones
患者的影像和植入物分析已经证明了体内硬-硬髋关节置换术的边缘负荷。在边缘加载条件下的试验性髋关节模拟器测试与同心条件相比，产生了与临床相关的硬上硬轴承的磨损率。然而，这样的测试既耗时又昂贵。开发了一种能够考虑实际轴承几何形状的快速计算边缘载荷模型(Python边缘载荷(PYEL)--准静态、刚性、无摩擦)。这项研究的目的是在∼0.5 mm的典型实验测量误差范围内预测分离。根据可比的有限元(FE)模型(包括惯性和摩擦)和先前存在的56个病例的实验测试数据，对该模型进行了验证和验证，涵盖了各种模拟的杯子方向、位置、组织张力和加载环境。PYEL模型与更复杂的计算模型和实验结果都符合得很好。与有限元模型相比，无惯性假设对最大分离度预测影响不大。在高接触力的情况下，无摩擦的假设有更大的影响(误差高达∼5%)。PYEL模型能够预测在∼0.3 mm范围内的实验最大分离。因此，它可以用来优化实验测试计划，并有效地调查更广泛的场景和变量。它还可以通过识别衬垫上不易通过实验测量的接触位置，帮助解释在实验测试中看到的趋势和损坏模式。
Patient imaging and explant analysis has shown evidence of edge loading of hard-on-hard hip replacements in vivo. Experimental hip simulator testing under edge loading conditions has produced increased, clinically-relevant, wear rates for hard-on-hard bearings when compared to concentric conditions. Such testing, however, is time consuming and costly. A quick running computational edge loading model (Python Edge Loading (PyEL) - quasi-static, rigid, frictionless), capable of considering realistic bearing geometries, was developed. The aim of this study was to produce predictions of separation within the typical experimental measurement error of ∼0.5 mm. The model was verified and validated against comparable finite element (FE) models (including inertia and friction) and pre-existing experimental test data for 56 cases, covering a variety of simulated cup orientations, positions, tissue tensions, and loading environments. The PyEL model agreed well with both the more complex computational modelling and experimental results. From comparison with the FE models, the assumption of no inertia had little effect on the maximum separation prediction. With high contact force cases, the assumption of no friction had a larger effect (up to ∼5% error). The PyEL model was able to predict the experimental maximum separations within ∼0.3 mm. It could therefore be used to optimise an experimental test plan and efficiently investigate a much wider range of scenarios and variables. It could also help explain trends and damage modes seen in experimental testing through identifying the contact locations on the liner that are not easily measured experimentally.