Fan Wei, Zhang Chi, Wang Qingdong, Zhang Dongxiang, Guo Lixin
School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2021 Oct 25;38(5):877-884. doi: 10.7507/1001-5515.202102010.
The human spine injury and various lumbar spine diseases caused by vibration have attracted extensive attention at home and abroad. To explore the biomechanical characteristics of different approaches for lumbar interbody fusion surgery combined with an interspinous internal fixator, device for intervertebral assisted motion (DIAM), finite element models of anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) are created by simulating clinical operation based on a three-dimensional finite element model of normal human whole lumbar spine. The fusion level is at L4-L5, and the DIAM is implanted between spinous process of L4 and L5. Transient dynamic analysis is conducted on the ALIF, TLIF and LLIF models, respectively, to compute and compare their stress responses to an axial cyclic load. The results show that compared with those in ALIF and TILF models, contact forces between endplate and cage are higher in LLIF model, where the von-Mises stress in endplate and DIAM is lower. This implies that the LLIF have a better biomechanical performance under vibration. After bony fusion between vertebrae, the endplate and DIAM stresses for all the three surgical models are decreased. It is expected that this study can provide references for selection of surgical approaches in the fusion surgery and vibration protection for the postsurgical lumbar spine.
振动引起的人体脊柱损伤及各种腰椎疾病已引起国内外广泛关注。为探究腰椎椎间融合手术联合棘突间内固定器（DIAM）不同入路的生物力学特性，基于正常人体全腰椎三维有限元模型模拟临床操作，建立了前路腰椎椎间融合术（ALIF）、经椎间孔腰椎椎间融合术（TLIF）和侧方腰椎椎间融合术（LLIF）的有限元模型。融合节段为L4-L5，DIAM植入L4与L5棘突之间。分别对ALIF、TLIF和LLIF模型进行瞬态动力学分析，计算并比较它们对轴向循环载荷的应力响应。结果表明，与ALIF和TILF模型相比，LLIF模型中终板与椎间融合器之间的接触力更高，而终板和DIAM中的冯·米塞斯应力更低。这意味着LLIF在振动作用下具有更好的生物力学性能。椎体间骨融合后，三种手术模型的终板和DIAM应力均降低。期望本研究能为融合手术中手术入路的选择及术后腰椎的振动防护提供参考。
