坐位旋转手法对腰椎内在应力的实时监测

Real-time measure of intra-stress of lumbar during simulating rotatory manipulation

目的:研究坐位旋转手法时对腰椎内在应力分布的特点。方法:使用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:正常腰椎在旋转手法作用时应力主要集中在椎体、终板和椎间盘处。退变腰椎在手法作用时应力主要集中在L4小关节的下关节突和椎弓,且应力分布集中。结论:(1)坐位腰椎旋转手法时,对于正常腰椎应力主要作用于椎体、终板和椎间盘等前部结构。(2)对于退变腰椎,应力主要作用于后部结构,并且所受应力分布集中,易损伤小关节、椎弓。

Objective: To study the traits of intra-stress distribution of lumbar during rotatory manipulation. Methods: A 3D finite element system of lumbar L4,5 was set up through Mimics software system handling normal lumbar L4,5 CT images. The lumbar rotatory manipulation was decomposed by principium of manipulation. The parameters of mechanics were analyzed by the finite element system. The change of intra-stress distribution was displayed in lumbar disc simultaneously during simulating manipulation. Results: For normal lumbar, the stress mainly distributed in the body of vertebra, endplate and lumbar disc during simulating manipulation. However, the stress mainly distributed in the arch of vertebra and inferior articular process of L4 for degenerative lumbar. Conclusions: During the lumbar rotatory manipulation, the stress on normal lumbar mainly locate on the anterior area, such as body of vertebra, endplate and lumbar disc. The stress on degenerative lumbar mainly locate on the posterior area. The distribution of stress on degenerative lumbar was more concentrative, therefore injury was more common on facet joint and arch of vertebra.