Department of Mechanical Engineering, Tsinghua University, Beijing 100086, China; Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China.
Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China.
Clin Biomech (Bristol). 2021 Apr;84:105339. doi: 10.1016/j.clinbiomech.2021.105339. Epub 2021 Mar 26.
Anterior lumbar interbody fusion combined with supplementary fixation has been widely used to treat lumbar diseases. However, few studies have investigated the influence of fixation options on facet joint force and cage subsidence. The aim of this study was to explore the biomechanical performance of anterior lumbar interbody fusion with various fixation options under both static and vertical vibration loading conditions.
A previously validated finite element model of the intact L1-5 lumbar spine was employed to compare five conditions: (1) Intact; (2) Fusion alone; (3) Fusion combined with anterior lumbar plate; (4) Fusion combined with Coflex-F fixation; (5) Fusion combined with bilateral pedicle screw fixation. The models were analyzed under static and vertical vibration loading conditions respectively.
Bilateral pedicle screws provided highest stability at surgical level. Applying supplementary fixation diminished the dynamic responses of lumbar spine. Compared with anterior lumbar plate and Coflex-F device, bilateral pedicle screws decreased the stress responses of the endplates and cage under both static and vibration conditions, while increased the facet joint force at adjacent levels. As for comparison between Coflex-F device and anterior lumbar plate, results showed a similarity in biomechanical performance under static loading, and a slightly higher dynamic response of the latter under vertical vibration.
The biomechanical performance of lumbar spine was significantly influenced by the variation of fixations under both static and vibration conditions. Bilateral pedicle screws showed advantages in stabilizing surgical segment and relieving cage subsidence, but may increase the facet joint force at adjacent levels.
前路腰椎椎体间融合联合辅助固定已广泛应用于治疗腰椎疾病。然而，很少有研究探讨固定方式对小关节力和 cage 下沉的影响。本研究旨在探讨前路腰椎椎体间融合术在静态和垂直振动加载条件下不同固定方式的生物力学性能。
采用已验证的完整 L1-5 腰椎有限元模型，比较了 5 种情况：（1）完整；（2）融合术；（3）融合术联合前路钢板；（4）融合术联合 Coflex-F 固定；（5）融合术联合双侧椎弓根螺钉固定。模型分别在静态和垂直振动加载条件下进行分析。
双侧椎弓根螺钉在手术节段提供了最高的稳定性。应用辅助固定降低了腰椎的动态响应。与前路钢板和 Coflex-F 装置相比，双侧椎弓根螺钉在静态和振动条件下降低了终板和 cage 的应力响应，同时增加了相邻节段的小关节力。Coflex-F 装置与前路钢板的比较结果表明，在静态加载下，生物力学性能相似，而在垂直振动下，后者的动态响应略高。
在静态和振动条件下，固定方式的变化对腰椎的生物力学性能有显著影响。双侧椎弓根螺钉在稳定手术节段和减轻 cage 下沉方面具有优势，但可能会增加相邻节段的小关节力。
