坐位腰椎旋转手法时腰椎单元内在应力和位移的实时监测

目的:用三维有限元法,分析施行坐位腰椎旋转手法时退变腰椎单元的内在应力及位移分布的特点,以探讨手法的作用机制、安全性及其合理性。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。观察手法作用时腰椎间盘的位移和内在应力的变化。结果:最大的应力集中点分布于环椎体峡部、椎弓根、上位椎体小关节面的下端。椎间盘的应力集中分布于环前外侧部,右后外侧部应力大于左后外侧部。最大位移出现在上位椎体的上关节。左侧小关节面相对位移较大,左侧椎间孔变大;右侧椎小关节面间移位小,右侧椎间孔变小,椎间盘右后外侧部向后突出。结论:模拟坐位腰椎旋转手法时,向健侧旋转优于向患侧旋转。

Real-time measure of displacement and intra-stress of lumbar unit during simulating rotation manipulation

Objective: To study the displacement and intra-stress distribution of degenerate lumbar disc during rotation manipulation by using 3D finite element system,so as to explore the mechanism of action,safety and rationality of manipulation.Methods: CT images of normal lumbar L4,5 were adopted,and 3D finite element system of lumbar L4,5 was produced by using Mimics software systemy.Based on the principle of manipulation,the lumbar rotation manipulation was decomposed,and many kinds of mechanical parameters were calculated and analyzed using the 3D finite element system.The changes of intra-stress distribution and the displacement of the lumbar disc during simulating manipulation were observed.Results: During the rotation manipulation,the end max-stress distributed in the isthmus,the pedicle of vertebral,and the superior articula facet.The end max-stress of lumbar disc distributed in the anterior-lateral side,and the stress of the right-posterior-lateral side was bigger than that of the opposite side.The max-displacemen was on the top of the superior articular facet.The displacement of the left articular facet was larger than that of the right articular facet,the same to the cervical foraminal area.The right-posterior-lateral disc protruded toward back-inner.Conclusion: It is more rational for rotation manipulation toward the healthy side.