Department of Orthopedics, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
Xi'an Jiaotong University, Xi'an, 710049, China.
Sci Rep. 2023 Jul 13;13(1):11354. doi: 10.1038/s41598-023-32624-2.
There are various internal fixation methods in treating lumbosacral spinal tuberculosis. The study compared the stability and stress distribution in surrounding tissues/implants, such as discs, endplates and screw-rod internal fixation system, etc. when applying three different lumbar internal fixation methods to treat lumbosacral spinal tuberculosis. A finite element model was constructed and validated. The spinal stability was restored using three methods: a titanium cage with lateral double screw-rod fixation (group 1), autologous bone with posterior double screw-rod fixation (group 2), and a titanium cage with posterior double screw-rod fixation (group 3). For comparison, group 4 represented the intact L3-S1 spine. Finally, a load was applied, and the ranges of motion and Von Mises stresses in the cortical endplates, screw-rod internal fixation system and cortical bone around the screws in the different groups were recorded and analyzed. All six ranges of motion (flexion, extension, left/right lateral bending, left/right rotation) of the surgical segment were substantially lower in groups 1 (0.53° ~ 1.41°), 2 (0.68° ~ 1.54°) and 3 (0.55° ~ 0.64°) than in group 4 (4.48° ~ 10.12°). The maximum stress in the screw-rod internal fixation system was clearly higher in group 2 than in groups 1 and 3 under flexion, left/right lateral bending, and left/right rotation. However, in extension, group 1 had the highest maximum stress in the screw-rod internal fixation system. Group 2 had the lowest peak stresses in the cortical endplates in all directions. The peak stresses in the cortical bone around the screws were higher in group 1 and group 2 than in group 3 in all directions. Thus, titanium cage with posterior double screw-rod fixation has more advantages in immediate reconstruction of lumbosacral spinal stability and prevention of screw loosening.
治疗腰骶段脊柱结核有多种内固定方法。本研究比较了三种不同腰椎内固定方法治疗腰骶段脊柱结核时，对周围组织/植入物（如椎间盘、终板和钉棒内固定系统等）的稳定性和应力分布的影响。构建并验证了有限元模型。采用三种方法恢复脊柱稳定性：带侧方双钉棒固定的钛笼（1 组）、后路双钉棒固定的自体骨（2 组）和后路双钉棒固定的钛笼（3 组）。为了比较，第 4 组代表完整的 L3-S1 脊柱。最后，施加负载，记录和分析各组皮质终板、钉棒内固定系统和螺钉周围皮质骨的运动范围和 Von Mises 应力。手术节段的所有六个运动范围（屈伸、左右侧弯、左右旋转）在 1 组（0.53°1.41°）、2 组（0.68°1.54°）和 3 组（0.55°0.64°）均明显低于 4 组（4.48°10.12°）。在屈伸、左右侧弯和左右旋转时，2 组钉棒内固定系统的最大应力明显高于 1 组和 3 组。然而，在伸展时，1 组钉棒内固定系统的最大应力最高。各组中，2 组皮质终板在各个方向的峰值应力最低。在各个方向上，1 组和 2 组螺钉周围皮质骨的峰值应力均高于 3 组。因此，后路双钉棒固定钛笼在腰骶段脊柱即刻重建稳定性和防止螺钉松动方面具有更多优势。
