Donaldson Finn E, Nyman Edward, Coburn James C
Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Office of Medical Products and Tobacco, U.S. Food and Drug Administration, Silver Spring, MD, USA.
J Biomech. 2015 Jul 16;48(10):1828-35. doi: 10.1016/j.jbiomech.2015.04.037. Epub 2015 May 5.
Manufacturers and investigators of Total Hip Replacement (THR) bearings require tools to predict the contact mechanics resulting from diverse design and loading parameters. This study provides contact mechanics solutions for metal-on-metal (MoM) bearings that encompass the current design space and could aid pre-clinical design optimization and evaluation. Stochastic finite element (FE) simulation was used to calculate the head-on-cup contact mechanics for five thousand combinations of design and loading parameters. FE results were used to train a Random Forest (RF) surrogate model to rapidly predict the contact patch dimensions, contact area, pressures and plastic deformations for arbitrary designs and loading. In addition to widely observed polar and edge contact, FE results included ring-polar, asymmetric-polar, and transitional categories which have previously received limited attention. Combinations of design and load parameters associated with each contact category were identified. Polar contact pressures were predicted in the range of 0-200 MPa with no permanent deformation. Edge loading (with subluxation) was associated with pressures greater than 500 MPa and induced permanent deformation in 83% of cases. Transitional-edge contact (with little subluxation) was associated with intermediate pressures and permanent deformation in most cases, indicating that, even with ideal anatomical alignment, bearings may face extreme wear challenges. Surrogate models were able to accurately predict contact mechanics 18,000 times faster than FE analyses. The developed surrogate models enable rapid prediction of MoM bearing contact mechanics across the most comprehensive range of loading and designs to date, and may be useful to those performing bearing design optimization or evaluation.
全髋关节置换（THR）轴承的制造商和研究人员需要工具来预测不同设计和载荷参数所导致的接触力学情况。本研究为金属对金属（MoM）轴承提供了接触力学解决方案，涵盖了当前的设计空间，并有助于临床前设计优化和评估。采用随机有限元（FE）模拟来计算设计和载荷参数的五千种组合情况下的股骨头与髋臼杯之间的接触力学。有限元结果用于训练随机森林（RF）代理模型，以快速预测任意设计和载荷情况下的接触斑尺寸、接触面积、压力和塑性变形。除了广泛观察到的极性和边缘接触外，有限元结果还包括环形极性、非对称极性和过渡类别，这些类别此前受到的关注有限。确定了与每种接触类别相关的设计和载荷参数组合。预测的极性接触压力在0 - 200 MPa范围内，无永久变形。边缘加载（伴有半脱位）与大于500 MPa的压力相关，在83%的情况下会引起永久变形。过渡边缘接触（半脱位较小）在大多数情况下与中等压力和永久变形相关，这表明即使在理想的解剖对齐情况下，轴承仍可能面临极端磨损挑战。代理模型能够比有限元分析快18000倍准确预测接触力学。所开发的代理模型能够在迄今为止最全面的载荷和设计范围内快速预测金属对金属轴承的接触力学，可能对进行轴承设计优化或评估的人员有用。
