有限元法对PVP术后邻近椎体应力平衡点的研究  

Study on stress balance of adjacent vertebral body after PVP by finite element method

作　　者：李飞虎[1] 谢恩[2] 郝定均[2] 吴起宁[2] 樊勇[2] 徐斌斌[2] 

机构地区：[1]陕西中医药大学,712046 [2]西安交通大学医学部附属红会医院脊柱外科腰椎病区,710054

出　　处：《美中国际创伤杂志》2017年第1期11-13,34,共4页U.S.Chinese International Journal of Traumatology

摘　　要：目的：应用有限元法研究椎体成形术中骨水泥的注入量与分布范围对邻近椎体所受应力以及疼痛改善的影响。方法：收集L2椎体骨质疏松性压缩骨折病人CT平扫资料，利用Mimics、Ansys等三维椎体分析软件建立骨质疏松性压缩骨折的三维有限元模型，模拟PVP手术过程，设定与术中操作相似的骨水泥剂量、形态以及骨水泥的分布，在轴向加载500N压力状态下，记录L1下终板、L3上终板的应力，从而比较手术后邻近椎体所受应力的变化，结合分析病人症状恢复程度，研究三者皆宜的骨水泥注入量与弥散范围。结果：完成L2椎体骨质疏松性压缩骨折三维有限元模型的建立。垂直载荷下，测得术前L1下终板、L3上终板应力值分别为4．08Mpa、4．99Mpa；L1椎体下终板在注入4ml骨水泥灌注后单、双侧弥散应力值分别为4．49Mpa、4．38Mpa；在注入6m]骨水泥灌注后单、双侧弥散应力值分别为4．76Mpa、4．50Mpa；L3椎体上终板在注入4ml骨水泥灌注后单、双侧弥散应力值分别为5．23Mpa、5．14Mpa，在注入6ml骨水泥灌注后单、双侧弥散应力值分别为5．45Mpa、5．09Mpa。邻近椎体应力随骨水泥注入量呈正比例增大，同等量骨水泥于双侧弥散组所产生应力增幅效应较单侧弥散组小。结论：骨水泥的注入量和分布范围可对邻近椎体所受应力产生直接影响。治疗剂量下较小值的骨水泥注入量和双侧分布可能降低邻近椎体发生骨折的风险。Objective： To analyze the biomechanical effect and pain improvement of the volume and distribution of bone cement on the adjacent vertebrae during percutaneous vertebroplasty （PVP） using finite element method. Methods： CT non-contrast enhanced scan data of L2 osteoporotic compression fracture was collected. Three-dimensional finite model of osteoporosis compression fracture was established using Mimics and Ansys software. According to the volume and distribution of bone cement in PVP, given about 500N axial loading and record the stress of L1 lower endplate and L3 upper endplate to compare the force distribution of the adjacent vertebrae, combined with patient symptom recovery, then study the bone cement injection volume and diffusion range which was suitable for all. Results： Three-dimensional model with finite element mesh was established successfully. Under the vertical loading, the preoperative stress values of L1 and L3 were 4.08Mpa and 4.99Mpa respectively. After 4ml and 6ml bone cement perfused into L1 lower endplate, unilateral and bilateral Von Mises stress were 4.49Mpa, 4.38Mpa and 4.76Mpa, 4.50Mpa respectively. After 4ml and 6ml bone cement perfused into L3 upper endplate, unilateral and bilateral Von Mises stress were 5.23Mpa, 5.14Mpa and 5.45Mpa, 5.09Mpa respectively. The stress of adjacent vertebral body in proportion to the amount of bone cement injection, and the effect of the same amount of bone cement on the stress amplification in bilateral diffusion group was smaller than that in unilateral group. Conclusion： The amount and distribution of bone cement can directly influence the stress of adjacent vertebral body, small amount of bone cement injection under the treatment dosage and bilateral distribution may reduce the risk of adjacent vertebral fracture.

关 键 词：骨质疏松性椎体压缩骨折 椎体成形术 有限元分析 生物力学 

分 类 号：R683.2[医药卫生—骨科学]