Wu J S, Chen J H
Department of Mechanical Engineering, National Chung-Hsing University, Taichung, Taiwan 402, ROC.
Med Eng Phys. 1996 Apr;18(3):215-24. doi: 10.1016/1350-4533(95)00027-5.
The purpose of this study is to clarify the mechanical behaviour of spinal motion segments through a proper numerical model. The model constructed can give correct information and provide medical fields with valuable guidance in solving clinical problems occurring in the spine. A three-dimensional poroelastic finite element model of spinal motion segments is constructed and a mixed formulation is introduced. The geometry of the model is automatically formed from a series of CT-scanning images. Vertebral column, intervertebral joint, facet joints and ligaments are all included in the model. The contact surface of facet joints is considered as the inclined boundary. Such inclination is imposed when the contact surface is under compression. Ligaments surrounding the vertebral body and the intervertebral disc are put into the model when they are under tension. Iteration is implemented in the computing process to meet such boundary characteristics of facet joints and ligaments. Prediction of the mechanical behaviour in the segment under long term creep loading, is demonstrated using the current algorithm. Results show that the model and corresponding numerical procedures developed here can simulate the mechanical behaviour of the spinal motion segments properly.
本研究的目的是通过合适的数值模型阐明脊柱运动节段的力学行为。所构建的模型能够给出正确的信息，并为医学领域解决脊柱出现的临床问题提供有价值的指导。构建了脊柱运动节段的三维多孔弹性有限元模型，并引入了混合公式。该模型的几何形状由一系列CT扫描图像自动生成。模型中包含了脊柱、椎间关节、小关节和韧带。小关节的接触面被视为倾斜边界。当接触面受压时施加这种倾斜。椎体和椎间盘周围的韧带在受拉时被纳入模型。在计算过程中进行迭代以满足小关节和韧带的这种边界特性。使用当前算法演示了长期蠕变载荷下节段力学行为的预测。结果表明，本文开发的模型和相应的数值程序能够正确模拟脊柱运动节段的力学行为。
