School of Mechatronics Engineering and Automation, Shanghai University, Shanghai, China; Spinal Deformity Clinical and Research Center of Anhui Province, Fuyang, Anhui, China.
School of Mechatronics Engineering and Automation, Shanghai University, Shanghai, China.
World Neurosurg. 2023 Dec;180:e429-e439. doi: 10.1016/j.wneu.2023.09.084. Epub 2023 Sep 25.
OBJECTIVE: The aim of this study was to compare the biomechanical performance of 6 pedicle screw internal fixation strategies for the treatment of burst fractures of the thoracolumbar spine using finite element (FE) analysis. METHODS: A finite element model of the T11-L3 thoracolumbar segment was established to simulate L1 vertebral burst fractures, and 6 models were conducted under multidirectional loading conditions: P2-D2, P1-D1, P2-D1,P1-D, P1-BF-D1, and P1-UF-D1. The range of motion (ROM) in the T12-L2 region and the von Mises stresses of pedicle screws and rods under the 6 internal fixation models were mainly analyzed. RESULTS: The maximum ROM and von Mises stress were obtained under flexion motion in all models. The P1-BF-D1 model had the least ROM and screw stress. However, when the injured vertebra was not nailed bilaterally, the P1-UF-D1 model had the smallest ROM; the maximum von Mises stress on the screw and rod was remarkably higher than that recorded in the other models. Moreover, the P2-D1 model had a ROM similar to that of the P1-D2 model, but with lower screw stress. The 2 models outperformed the P1-D1 model in all 6 conditions. The P2-D2 model had a similar ROM with the P2-D1 model; nevertheless, the maximum von Mises stress was not substantially reduced. CONCLUSIONS: The P1-BF-D1 model exhibited better stability and less von Mises stress on the pedicle screws and rods, thereby reducing the risk of screw loosening and fracture. The P2-D1 internal fixation approach is recommended when the fractured vertebrae are not nailed bilaterally.
目的:本研究旨在通过有限元(FE)分析比较 6 种椎弓根螺钉内固定策略治疗胸腰椎爆裂骨折的生物力学性能。
方法:建立 T11-L3 胸腰椎节段的有限元模型,模拟 L1 椎体爆裂骨折,在多向加载条件下对 6 种模型进行研究:P2-D2、P1-D1、P2-D1、P1-D、P1-BF-D1 和 P1-UF-D1。主要分析 T12-L2 节段的活动范围(ROM)和 6 种内固定模型中椎弓根螺钉和棒的 von Mises 应力。
结果:所有模型在屈伸运动中均获得最大 ROM 和 von Mises 应力。P1-BF-D1 模型的 ROM 最小,螺钉和棒的 von Mises 应力最小。然而,当受伤椎体未双侧钉固时,P1-UF-D1 模型的 ROM 最小;螺钉和棒上的最大 von Mises 应力显著高于其他模型。此外,P2-D1 模型的 ROM 与 P1-D2 模型相似,但螺钉应力较低。在所有 6 种情况下,这 2 种模型的 ROM 均优于 P1-D1 模型。P2-D1 模型的 ROM 与 P2-D1 模型相似;然而,最大 von Mises 应力并未显著降低。
结论:P1-BF-D1 模型表现出更好的稳定性和椎弓根螺钉和棒上较低的 von Mises 应力,从而降低螺钉松动和断裂的风险。当骨折椎体未双侧钉固时,建议采用 P2-D1 内固定方法。
Orthop Surg. 2024-10