Wu J Z, Herzog W, Ronsky J
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
J Biomech. 1996 Oct;29(10):1263-81. doi: 10.1016/0021-9290(96)00051-6.
The articular contact surfaces in human and animal joints are highly variable. Articular cartilage thickness and the material properties of the cartilage vary as a function of location in the joint and may also change in the pathologic state. In order to study practical joint contact problems, we extended the model for the contact of two biphasic cartilage layers proposed by Ateshian et al. [J. Biomechanics 27, 1347-1360 (1994)] by combining the assumption of the kinetic relationship from classical contact mechanics with the joint contact model for biphasic articular cartilage. In order to illustrate the characteristics of the proposed model, the contact problem was solved numerically for different curvatures of the contact surfaces, and for different thicknesses and material properties of the cartilage layers. Each cartilage layer was assumed to have constant thickness within the contact region. The contact radius, the relative displacement between the contacting bodies, contact pressure, and the stress distributions within the cartilage layers were calculated by applying a step load for a time period of 200 s. The contact radius was found to be sensitive to the change in thickness of the cartilage, and was not very sensitive to the change in the material property of the cartilage. The peak effective stress and the maximal shear stress were predicted to occur at the cartilage-bone interface for all simulated cases, which is in agreement with other theoretical research and supports the experimental findings in the literature on the origins of cartilage damage. For articular cartilage layers of different thicknesses, the stresses in the thick layer were found to be higher than those in the thin layer. Compared to other models of joint contact, the present model offers more possibilities for investigating practical applications, such as simulating the effects associated with cartilage degeneration in diseases such as osteoarthritis, and comparing theoretical predictions with experimental measurements of pressure distribution and contact area in joints.
人类和动物关节中的关节接触面具有高度的变异性。关节软骨的厚度以及软骨的材料特性会随着在关节中的位置而变化，并且在病理状态下也可能发生改变。为了研究实际的关节接触问题，我们扩展了Ateshian等人[《生物力学杂志》27, 1347 - 1360 (1994)]提出的两层双相软骨接触模型，将经典接触力学中的动力学关系假设与双相关节软骨的关节接触模型相结合。为了说明所提出模型的特性，针对不同的接触面曲率、不同的软骨层厚度和材料特性，对接触问题进行了数值求解。假设每个软骨层在接触区域内具有恒定的厚度。通过在200秒的时间段内施加阶跃载荷，计算了接触半径、接触物体之间的相对位移、接触压力以及软骨层内的应力分布。发现接触半径对软骨厚度的变化敏感，而对软骨材料特性的变化不太敏感。在所有模拟情况下，预计峰值有效应力和最大剪应力会出现在软骨 - 骨界面处，这与其他理论研究一致，并支持了文献中关于软骨损伤起源的实验结果。对于不同厚度的关节软骨层而言，发现厚层中的应力高于薄层中的应力。与其他关节接触模型相比，本模型为研究实际应用提供了更多可能性，例如模拟骨关节炎等疾病中与软骨退变相关的影响，以及将理论预测与关节压力分布和接触面积的实验测量结果进行比较。
