Faculty of Sports Science, Ningbo University, Ningbo, China.
Doctoral School on Safety and Security Sciences, Óbuda University, Budapest, Hungary.
Medicine (Baltimore). 2022 Sep 9;101(36):e30419. doi: 10.1097/MD.0000000000030419.
To explore the biomechanical characteristics of 2 posterior bilateral pedicle screw fixation methods using finite element analysis.
A normal L3-5 finite element model was established. Based on the verification of its effectiveness, 2 different posterior internal fixation methods were simulated: bilateral pedicle screws (model A) were placed in the L3 and L5 vertebral bodies, and bilateral pedicle screws (model B) were placed in the L3, L4, and L5 vertebral bodies. The stability and stress differences of intervertebral discs, endplates, screws, and rods between models were compared.
Compared with the normal model, the maximum stress of the range of motion, intervertebral disc, and endplate of the 2 models decreased significantly. Under the 6 working conditions, the 2 internal fixation methods have similar effects on the stress of the endplate and intervertebral disc, but the maximum stress of the screws and rods of model B is smaller than that of model A.
Based on these results, it was found that bilateral pedicle screw fixation in 2 vertebrae L3 and L5 can achieve similar stability as bilateral pedicle screw fixation in 3 vertebrae L3, L4, and L5. However, the maximum stress of the screw and rod in model B is less than that in model A, so this internal fixation method can effectively reduce the risk of fracture. The 3-dimensional finite element model established in this study is in line with the biomechanical characteristics of the spine and can be used for further studies on spinal column biomechanics. This information can serve as a reference for clinicians for surgical selection.
通过有限元分析探讨两种后路双侧椎弓根螺钉固定方法的生物力学特性。
建立正常 L3-5 有限元模型。在验证其有效性的基础上，模拟两种不同的后路内固定方法：双侧椎弓根螺钉（模型 A）分别置于 L3 和 L5 椎体，双侧椎弓根螺钉（模型 B）分别置于 L3、L4 和 L5 椎体。比较模型间椎间盘、终板、螺钉和棒的稳定性和应力差异。
与正常模型相比，两种模型的活动范围、椎间盘和终板的最大应力均显著降低。在 6 种工作条件下，两种内固定方法对终板和椎间盘的应力影响相似，但模型 B 的螺钉和棒的最大应力小于模型 A。
根据这些结果发现，双侧椎弓根螺钉固定在 2 个椎体 L3 和 L5 可以达到与双侧椎弓根螺钉固定在 3 个椎体 L3、L4 和 L5 相似的稳定性。然而，模型 B 中螺钉和棒的最大应力小于模型 A，因此这种内固定方法可以有效降低骨折风险。本研究建立的三维有限元模型符合脊柱生物力学特征，可用于进一步研究脊柱柱生物力学。这些信息可以为临床医生的手术选择提供参考。
