Full-field comparisons between strains predicted by QCT-derived finite element models of the scapula and experimental strains measured by digital volume correlation
Full-field comparisons between strains predicted by QCT-derived finite element models of the scapula and experimental strains measured by digital volume correlation
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DOI：
10.1016/j.jbiomech.2020.110101
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发表时间：
2020-12-02
影响因子：
2.4
通讯作者：
Ferreira, Louis
中科院分区：
文献类型：
--
作者：
Kusins, Jonathan;Knowles, Nikolas;Ferreira, Louis
肩关节的特定对象有限元模型(FEMS)可用于临床前评估关节置换设计。然而，为了确保得出准确的结论，实验验证是至关重要的。本研究的目的是通过与使用数字体积相关(DVC)测量的全场实验应变进行比较，来评估特定受试者肩胛骨FEMS所产生的应变预测的准确性。在微型CT扫描仪中，使用定制的六足机器人对三具身体肩骨进行机械加载。使用BoneDVC对合成的实验全场应变进行量化。使用三种不同的密度-模数关系来生成肩胛骨FEM来指定材料属性。模拟了两种边界条件：DVC位移驱动和外加力驱动。第三，将DVC测量结果与有限元预测的主应变进行了比较。对于外力BCS，预测应变与实际应变之间的一致性较差(斜率范围为0.16-0.19，r(2)范围为0.04-0.30)。使用DVC-位移BCS(斜率范围：0.54-0.59，r(2)范围：0.73-0.75)可提高一致性。应变预测与用于DVC-位移BCS的密度-弹性关系无关，但是对于施加外力的BCS，在相关系数和截距方面存在差异。总体而言，这项研究利用全场DVC衍生的实验应变与具有不同材料特性和BCS的模型中的有限元预测应变进行比较。结果表明，当采用DVC-位移边界条件时，局部应变测量结果与有限元预测结果吻合较好。然而，由于使用外力BCS，性能受到影响。皇冠版权(C)2020由爱思唯尔有限公司出版。
Subject-specific finite element models (FEMs) of the shoulder can be used to evaluate joint replacement designs preclinically. However, to ensure accurate conclusions are drawn, experimental validation is critical. The objective of the current study was to evaluate the accuracy of strain predictions generated by subject-specific scapula FEMs through comparisons against full-field experimental strains measured using digital volume correlation (DVC). Three cadaveric scapulae were mechanically loaded using a custom-hexapod robot within a micro-CT scanner. BoneDVC was used to quantify resultant experimental full-field strains. Scapula FEMs were generated using three different density-modulus relationships to assign material properties. Two types of boundary conditions (BCs) were simulated: DVC-isplacement-driven or applied-force-driven. Third principal strains were compared between the DVC measurements and FEM predictions. With applied-force BCs, poor agreement was observed between the predicted and measured strains (slope range: 0.16-0.19, r(2) range: 0.04-0.30). Agreement was improved with the use of DVC-displacement BCs (slope range: 0.54-0.59, r(2) range: 0.73-0.75). Strain predictions were independent of the density-modulus relationship used for DVC-displacement BCs, but differences were observed in the correlation coefficient and intercept for applied-force BCs. Overall, this study utilized full-field DVC-derived experimental strains for comparison with FEM predicted strains in models with varying material properties and BCs. It was found that fair agreement can be achieved in localized strain measurements between DVC measurements and FEM predictions when DVC-displacement BCs are used. However, performance suffered with use of applied-force BCs. Crown Copyright (C) 2020 Published by Elsevier Ltd.