应用有限元分析单侧与双侧入路椎体成形后的生物力学变化*

摘要：基于1例椎体成形术患者的计算机断层影像资料，建立椎体L1~L2三维有限元模型，然后输入材料信息，设立边界条件，在有限元模型上建立轴向负载，模拟人体重力方向。根据结果评价单侧及双侧入路椎体成形后椎体单元的应力分布情况。随着施加负载的增加，应变和应力也逐渐增加，椎体呈现弹性性质，出现了近似线性的小变形情况。单侧椎体较双侧有较大的应力和应变。椎间盘出现应力集中现象，椎体的中部和相邻椎体的中上部，出现应力集中现象，椎体成形术单侧分布较双边分布有较大的应力。单纯从生物力学考虑，应用双侧注射比较单侧注射方法应力分布更加合理，提示临床要使单侧入路获得双侧入路的临床效果，需要改进单侧入路的穿刺点和穿刺路径以及注射方法。

Biomechanical changes following vertebroplasty by unilateral or bilateral approach: Finite element analysi

Abstract: A finite element model of L1-L2 was set up based on the CT scanning data of one patient undergoing vertebroplasty. The information of the material was input to set up the boundary condition. Axial load was exerted to the finite element model to simulate the gravity direction of human body to evaluate the stress distribution of the vertebral bodies after vertebroplasty by unilateral or bilateral approach. With the increasing load, the strain and stress became larger. The vertebral bodies appeared the property of elasticity with linear minor deformity. The vertebral bodies by unilateral approach had greater strain and stress, and the stress was concentrated at the disc, the middle of the vertebral bodies, and the middle and the superior part of the adjacent bodies. The stress distribution by unilateral approach was larger in percutaneous vertebroplasty. Considering the biomechanics, the stress distribution by bilateral approach is better than unilateral, indicating that the clinical doctors should improve the puncture site and pathway as well as the injection method, if they use unilateral approach.