人工腰椎间盘三维有限元模型的建立及其应力分析

目的 研究人工腰椎间盘三维有限元模型的建立及其应力分布。方法 利用有限元软件MSC MARK，建立人工椎间盘及L4-5运动节段的三维模型。并赋予各自生物材料特性，然后模拟腰椎节段的运动，研究人工椎间盘的应力分布。结果 建立了具有相应力学特性人工椎间盘和L4-5运动节段的模型。人工椎间盘的应力分布特点为：（1）在所有的运动状态中，滑动核及盖板的中心部位承受的应力最大，其次为滑动核在运动状态下偏向的部位；（2）滑动核及盖板上表面承受各自的下表面2-3倍的应力；（3）在所有的运动状态中，压缩状态下滑动核和盖板的中心部位承受的应力最大。结论 建立人工腰椎间盘三维有限元模型并进行其应力分析是可行的，结果是可信的。

Establishment of artificial lumbar intervertebral disc three-dimensional fmite element and its stress analysis

Objective To study artificial lumbar intervertebral disc three-dimensional finite element model and its stress state. Methods The three-dimensional finite element models of artificial lumbar intervertebral disc were established by finite element software MSC. MARK. While L4-5 motion segment from young healthy cadaver was created to give the models biomaterial characters. The vertebral disc of L4-5 was replaced by artificial lumbar intervertebral disc to make a model of an artificial disc replacement. Results After three-dimensional finite element models with biomaterial characters of artificial lumbar intervertebral disc and L4-5 motion segment had been created, the stress distribution of artificial lumbar intervertebral disc showed some characteristics as follows:1)The stress exerted in the center of polyethylene slide core and end plates is biggest in all motion states, the next exists at the deviated site while the polyethylene slide core set in motion. 2)The upper surface of polyethylene slide core and end plates bear 2-3 times stress as much as that of the lower surface. 3)The biggest stress exists in the center of polyethylene slide core and end plates during compression in all motion states. Conclusion Establishment of three-dimensional finite element models of artificial lumbar intervertebral disc and analysis of its stress are feasible. The results are reliable.