有限元分析过伸复位治疗胸腰椎压缩性骨折的椎间盘动态力学

A dynamic biomechanical analysis of the intervertebral disk following thoracolumbar spine compression fracture treated with hyperextending based on finite element method

背景:过伸复位法治疗胸腰椎压缩性骨折具有治疗效果好、费用低、损伤轻、疗效快等优点,但临床应用缺乏规范,对手法的作用机制研究相对不足。目的:利用有限元分析法观察过伸复位治疗胸腰椎压缩性骨折椎间盘的动态生物力学特性。方法:依据1例T12椎体单纯压缩性骨折患者的210层Dicom3.0标准的CT图片建立T12椎体单纯压缩性骨折的有限元模型,在对模型有效性进行验证后,模拟过伸复位手法,约束L2下端所有面,给T11椎体上端一个纵向牵引力,分别于T11,T12,L1椎骨棘突顶点给予一个方向垂直朝向椎体、大小为3.0cm的位移。程序运算,读取受压椎骨上下椎间盘的受力情况。结果与结论:建立了几何外型逼真、生物力学特性全面的胸腰段椎体压缩性骨折三维有限元模型。复位手法作用后椎间盘发生明显的牵张,在不同过伸支点椎间盘的受力不同。提示过伸复位治疗胸腰椎压缩性骨折疗效确切,椎间盘在骨折复位中发挥重要作用,利用有限元法分析传统手法的作用机制具有实验结果可靠、显示结果直观、节约资源以及手法模拟精确等优点。

BACKGROUND：Hyperextending treatment for thoracolumbar spine compression fracture has the advantages of good effect,low cost,light damage,and rapid effect.However,clinical application lacks of specification,the mechanism of practices is relative inadequate.OBJECTIVE：To explore the dynamic biomechanical characteristics of intervertebral disk with the treatment of thoracolumbar spine compression fracture by hyperextending based on finite element method.METHODS：The finite element model of compression fracture of T12 based on the 210-layer consecutive CT DICOM format images from one patient of compression fracture of T12 was constructed.The hyperextending was stimulated after effective verification of model.All surfaces of the lower of T12 was restrained,a vertical traction at the top of T11 was imposed,and a 3 cm-displacement towards the vertebral by three steps at the top of spinous process of T11,T12,and L1.The forces of the upper and lower intervertebral discs of compressed vertebrae were read by operational procedure.RESULTS AND CONCLUSION：A realistic appearance and full biomechanical properties 3D finite element model of thoracolumbar spine compression fracture was established.The intervertebral disks were obviously stretched after hyperextending.The stress of intervertebral disk is different,when the hyperextending fulcrum is different.It is indicated that the treatment effect of thoracolumbar spine compression fracture by hyperextending is exact.The intervertebral disk plays an important role in bone fracture reposition.The mechanism of traditional practices with finite element method has many advantages,such as reliable experimental results,intuitive results,resource conservation and accurate practices.