个体化精准穿刺椎体强化治疗不同类型骨质疏松性椎体压缩骨折的生物力学分析

Biomechanical analysis on treatment of different types of osteoporotic vertebral compression fractures with individualized precise puncture vertebral augmentation

背景:个体化精准穿刺入路是近年来提出椎体强化治疗的新型入路方式,并且已经取得了良好的临床疗效,但仍缺少相关生物力学研究。目的:采用有限元分析方法探讨个体化精准穿刺椎体强化治疗对骨质疏松性椎体压缩骨折椎体终板以及椎间盘生物力学的影响。方法:使用3例已完成个体化精准穿刺椎体强化治疗的骨质疏松性椎体压缩骨折患者术前和术后的CT影像资料,建立楔形型、双凹型、塌陷型术前和术后共6个模型。在椎体垂直方向加载500 N力矩和10 N/m旋转力矩,模拟正常椎体的生理活动,包括前屈、后伸、左侧弯、右侧弯、左旋转和右旋转,观察个体化精准穿刺椎体强化治疗后不同类型骨折椎体终板、邻近终板以及椎间盘的应力变化。结果与结论:①成功建立了个体化精准穿刺椎体强化术前和术后脊柱功能单元的三维有限元模型;②个体化精准穿刺椎体强化术后,楔形型、双凹型及塌陷型骨折椎体终板和邻近椎体终板的最大von Mises应力值均有一定程度的减小;楔形型邻近椎体T_(10)下终板和塌陷型邻近椎体L1上终板的术后最大von Mises应力值增加;③个体化精准穿刺椎体强化术后,3种有限元模型的相邻椎间盘整体最大von Mises应力值均减小;④结果表明,个体化精准穿刺椎体强化治疗可在一定程度上减轻楔形型、双凹型和塌陷型椎体终板的最大von Mises应力值,降低术后椎体再骨折的风险;此外,还可减轻椎间盘的最大von Mises应力值,理论上也能够在一定程度上缓解椎间盘退变。

BACKGROUND:The individualized precise puncture approach is a new approach proposed for vertebral body augmentation in recent years,and has achieved good clinical results,but there is still a lack of relevant biomechanical research.OBJECTIVE:To investigate the biomechanical effects of individualized precise puncture vertebral augmentation on the vertebral endplate and intervertebral disc of osteoporotic vertebral compression fracture using finite element analysis method.METHODS:A total of six preoperative and postoperative models of wedge type,biconcave type,and collapse type were established using the preoperative and postoperative CT imaging data of three osteoporotic vertebral compression fracture patients who had completed individualized precise puncture vertebral augmentation.500 N moment and 10 N/m rotation moment were loaded in the vertical direction of the vertebral body to simulate the normal physiological activities of the vertebral body,including forward flexion,back extension,left bending,right bending,left rotation,and right rotation,to observe the stress changes of endplates,adjacent endplates,and intervertebral discs of different types of fractured vertebral bodies after individualized precise puncture vertebral augmentation.RESULTS AND CONCLUSION:(1)Three-dimensional finite element models of preoperative and postoperative spinal functional units were successfully established.(2)After individualized precise puncture vertebral augmentation,the maximum von Mises stress values of wedge-shaped,biconcave,and collapsed fractured vertebral endplates and adjacent vertebral endplates were reduced to a certain extent.The postoperative maximum von Mises stress value increased in the T_(10) inferior endplate of the superior vertebral body with wedge deformity and the L1 superior endplate of the inferior vertebral body with collapsed deformity.(3)After individualized precise puncture vertebral augmentation,the overall maximum von Mises stress value of adjacent intervertebral discs in the three finite element models decreased.(4)The results show that individualized precise puncture vertebral augmentation can reduce the maximum von Mises stress value of the endplate of wedge-shaped deformity,biconcave deformity and collapsed vertebral body to a certain extent,and diminish the risk of postoperative vertebral body re-fracture.In addition,individualized precise puncture vertebral augmentation decreases the maximum von Mises stress value of the intervertebral disc,which can theoretically alleviate intervertebral disc degeneration to a certain extent.