三维有限元建模对椎体成形术骨水泥硬度的生物力学分析

Biomechanical Analysis of the Hardness of Bone Cement for Vertebroplasty with the Three-dimensional Finite Element Modeling

目的:通过分析不同骨水泥硬度在椎体成形术后对手术椎体邻椎的生物力学效应,寻找对术后邻椎新发骨折影响最小的骨水泥硬度范围。方法:根据患者椎体CT数据建立T12-L2椎体的三维有限元模型。验证正常椎体有限元模型生物力学的可靠性。再次模拟不同硬度的骨水泥注入L1椎体。分析椎体成形术后T12及L2椎体在屈伸、左右侧弯曲和左右方扭转载荷作用下的最大应力。结果:椎体有限元模型可以用于研究生物力学实验。骨水泥模型弹性模量逐渐升高,相邻T12椎体和L2椎体在屈伸活动下,容易发生新的骨折,且后伸运动影响最大;其他方向运动的作用下,邻椎应力均无显著变化。该患者骨水泥弹性模量的最适宜范围为1000~1500。结论:骨水泥弹性模量的增加可能会增加邻近椎体再次骨折的风险,为优化椎体成形术的临床治疗提供了一个新的视角。

Objective:The purpose of this study is to investigate the biomechanical effect of different bone cement hardness on adjacent vertebrae after vertebroplasty,and to find the range of bone cement hardness that has the least impact on postoperative adjacent vertebrae fracture.Methods:A three-dimensional finite element model of T12-L2 vertebral body was established based on CT data of the patient's vertebral body.The biomechanical reliability of the normal vertebral finite element model is verified.Again,bone cement of different hardness is injected into L1 vertebra.The maximum stresses of T12 and L2 vertebral bodies under flexion and extension,left and right side bending and left and right side torsion loading after vertebroplasty are analyzed.Results:Finite element model of vertebral body can be used to study biomechanical experiments.The elastic modulus of the bone cement model increased gradually,and the adjacent T12 vertebra and L2 vertebra are prone to new fractures under flexion and extension activities,with the greatest influence of posterior extension movement;Under the action of other direction movement,the stress of adjacent jobs does not change significantly.The optimal range of elastic modulus of bone cement in this patient is 1000~1500.Conclusion:Increased elastic modulus of bone cement may increase the risk of secondary fractures of adjacent vertebral bodies.Our study provides a new perspective for optimizing the clinical treatment of vertebroplasty.