坐位旋转手法对正常腰椎间盘内在应力和位移的实时监测的实验研究

Real-time measure of displacement and intra-stress of normal lumbar disc during simulating rotatory ma-nipulation in sitting position

目的:了解坐位旋转手法对正常腰椎间盘的内在应力及位移分布的特点。方法:使用正常L4—5腰椎CT片,以Mimics软件系统逐层重建,建立L4—5三维有限元模型。根据手法原理,将坐位腰椎旋转手法进行分解,把各项力学参数代入三维有限元模型进行计算分析。即时显示手法作用时腰椎间盘的位移和内在应力的变化。结果:纤维环旋转侧的前部所受压力和旋转对侧的后部受到张力都逐渐增加;旋转侧的前部出现明显垂直压缩,并向前、向外侧膨出移位;纤维环旋转对侧的后部出现拉伸变形,并向前、向内侧回缩移位。结论:模拟坐位腰椎旋转手法时,椎间盘在旋转侧的前部为压力主要集中区,同时在旋转对侧的后部为张力集中区。椎间盘的最大位移在旋转侧的前部上缘;旋转对侧的后部受到张力也相应出现拉伸。髓核内的应力和位移变化相对较小。

Objective：To study the trait of displacement and intra-stress distribution of normal lumbar disc during rotatory manipulation.Method：Sectional constructed with Mimics software system by normal lumbar L4-5 CT images. Set up a 3D finite element system of lumbar L4-5. The lumbar rotatory manipulation was decomposed by principium of manipulation. The parameter of mechanics was analyzed with the finite element system. The change of intra-stress distribution and displacement in lumbar disc simultaneous were displayed during simulating manipulation.Result：The intra-stress in the anterior part of the rotary side of annulus fibers was increasing gradually during rotatory manipulation. The intra-tension in the posterior part of opposite side of rotation was increasing gradually either. The anterior part of the rotaly side of annulus fibers was compressed obviously,and expanded into anterior and lateral. The posterior part of opposite side of rotation was extended, and the displacement was toward anterior and interior.Conclusion：During simulating lumbar rotatory manipulation, the stress mainly distributed in the anterior part of the rotary side of lumbar disc： the tension mainly distributed in the posterior part of the opposite side of the rotation. The maximal displacement lay in the anterior part of the rotary side of lumbar disc; the posterior part of opposite side of rotation was extended by the tension. The intra-stress and displacement of nucleus was comparatively lesser.