Validation of a new computational 6-DOF knee simulator during dynamic activities
Validation of a new computational 6-DOF knee simulator during dynamic activities
复制标题
DOI：
10.1016/j.jbiomech.2016.07.040
复制
发表时间：
2016-10-03
影响因子：
2.4
通讯作者：
Rullkoetter, Paul J.
中科院分区：
文献类型：
--
作者：
Fitzpatrick, Clare K.;Maag, Chase;Rullkoetter, Paul J.
最近开发了一种新的六自由度(6-DOF)关节模拟器，它有助于在比以前更真实的加载条件下对植入物进行测试。然而，典型的磨损测试可能非常耗时，需要数周或数月才能完成。经过验证的计算模型是对这些类型的长时间运行测试的理想补充。在这项研究中，开发了一种新型六自由度关节模拟器的计算模型，并进行了验证。对全膝关节置换术的假体进行了物理模拟和计算机模拟，并对实验和模型的关节力学进行了比较。在代表三种不同日常生活活动的负荷条件下，对两种全膝关节置换设计进行了运动学比较：深屈膝、步态和下台阶。该模型准确地再现了在物理模拟器中获得的运动，并适当区分了活动和植入物设计之间的差异。在两种植入物设计和所有三种动态活动中，前后平移和内外旋转的均方根差分别小于1.7 mm和1.4度。模型预测的接触面积、峰值和平均接触压力与实验测量值的均方根精度分别为20 mm(2)、9 Mpa和1 Mpa。六自由度关节模拟器的计算模型将是在代表活体环境的载荷条件下有效评估种植体力学的关键工具。这些模拟可以直接用于设备的比较，或者可以通过确定哪些活动和/或加载条件最好地解决特定的临床或设计问题，例如，开发用于磨损测试的最坏情况的加载分布，来帮助促进物理模拟器的最佳使用。(C)2016爱思唯尔有限公司。保留所有权利。
A new six-degree-of-freedom (6-DOF) joint simulator has recently been developed which facilitates testing of implants under more realistic loading conditions than has been possible previously. However, typical wear testing can be very time-consuming, taking weeks or months to complete. A validated computational model is an ideal complement to these types of long-running tests. In this study, a computational counterpart to the new 6-DOF joint simulator was developed and validated. Total knee replacement components were evaluated in both physical and computational simulations, and joint mechanics were compared between the experiment and the model. Kinematic comparisons were carried out for two total knee replacement designs, under loading conditions representative of three different activities of daily living: deep knee bend, gait, and stepdown. The model accurately reproduced the motions obtained in the physical simulator, and appropriately differentiated between activities and between implant designs. Root-mean-square differences in anterior-posterior translations and internal external rotations were less than 1.7 mm and 1.4 degrees, respectively, for both implant designs and all three dynamic activities. Contact area, and peak and average contact pressure predicted by the model matched experimental measurements with a root-mean-square accuracy of 20 mm(2), 9 MPa, and 1 MPa, respectively. The computational model of the 6-DOF joint simulator will be a key tool in efficient evaluation of implant mechanics under loading conditions representative of the in vivo environment. These simulations may be used directly in comparison of devices, or may aid in facilitating optimal usage of the physical simulator through determining which activities and/or loading conditions best address specific clinical or design issues, for example, development of worst-case loading profiles for wear testing. (C) 2016 Elsevier Ltd. All rights reserved.