腰椎间盘退变对软骨终板生物力学特性影响的有限元分析

目的　研究腰椎终板不同位点的压应力分布规律，分析腰椎间盘退变对软骨终板压应力的影响。 方法　选取一青壮年男性新鲜尸体的腰椎运动节段标本，螺旋CT机对腰椎运动节段进行连续CT扫描，利用有限元分析方法，建立L4/5运动节段有限元分析模型，在此基础上建立椎间盘退变模型。模拟椎间盘正常状态和椎间盘退变状态，在L4、L5椎体终板上选择具有代表性的结点，分别代表椎体终板正中部、左右侧边缘、后中部和前中部，对上下软骨终板压应力分布进行有限元分析。 结果　椎间盘退变组较正常组的终板压应力均显著增大，上下终板在轴向加载、前屈、后伸、左旋和右旋加载时椎间盘退变组较正常状态时应力分布均显著增大，具有统计学意义（P<0.05）。 结论　腰椎椎间盘退变因素对终板的应力分布有明显影响， 随着椎间盘退变，椎间盘软骨终板应力显著增大。

Finite element analysis of lumbar disc degeneration on the biomechanical properties of the cartilage endplate effects

Objective　To study the compressive stress properties of the lumbar endplate distribution of different sites, and analyze the impact of the biomechanical properties of the cartilage endplate lumbar disc degeneration.　Methods　A lumbar motion segment was obtained from a fresh corpse of young age, which then underwent continuous spiral CT scans to provide data for establishment of L4/5 motion segment finite element analysis model using the finite element method and subsequently for establishment of disc degeneration model. The intervertebral disc degeneration state and normal state were simulated, and nodes were selected on L4, L5 vertebral endplates represent the central area, the left and right margins, and the anterior-central area. Stress distribution was then performed on these areas to using finite element analysis. Results　Compared with the normal endplate, stress distribution were significantly increased on the disc degeneration group. Inferior endplate stress distribution in the end plates were significantly increased compared with the normal state when load was imposed in the axis, flexion, extension, left and right rotation (P<0.05).　Conclusions　The lumbar disc degeneration factors have a significant impact on the stress distribution endplate. Under the state of disc degeneration, endplate cartilage stress significantly increases.