Xu Yi-chun, Liu Shang-li, Zhang Mei-chao, Huang Dong-sheng, Wang Qi-you
Department of Orthopaedics, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China.
Zhonghua Wai Ke Za Zhi. 2004 Dec 22;42(24):1485-8.
To study vertebral body stress distribution of normal disc, post-Diskectomy and artificial disk respectively by 3-D finite element methods, and to explore artificial intervertebral disk insertion impact on stress distribution of vertebral body.
Models of normal disk, post-Diskectomy, artificial disk and L(4 - 5) motion segment were established by using finite element software MSC. MARK, then vertebral body stress was analyzed through model of L(4 - 5) motion segment respectively.
The vertebral body's stress was the smallest after insertion of artificial intervertebral disk (AID), and its stress distributed equally. But the stress under post-discectomy was bigger than the normal disc's in all the motion state. On the other hand, the stress distribution state of the post-discectomy changed while the spine were in different motion state, during the spine flexion, the stress in the anterior of vertebral body was the biggest; While extension, in the posterior and in right flexion state, the biggest stress was in the right. While vertical compression and rotation, the stress distributed equally.
The results illustrate that the vertebral body's stress is the smallest after insertion of AID in 3 groups of all motion state, and its stress distributes equally. But the level of vertebral body stress increases after discectomy comparing with the normal group. In generally, it is much more reasonable that the disc is reconstructed with AID because of the biomechanical effect on vertebral body made by AID insertion.
采用三维有限元方法分别研究正常椎间盘、椎间盘切除术后及人工椎间盘的椎体应力分布，探讨人工椎间盘植入对椎体应力分布的影响。
运用有限元软件MSC.MARK建立正常椎间盘、椎间盘切除术后、人工椎间盘及L(4 - 5)运动节段模型，然后通过L(4 - 5)运动节段模型分别分析椎体应力。
人工椎间盘植入后椎体应力最小，且应力分布均匀。但椎间盘切除术后在所有运动状态下的应力均大于正常椎间盘。另一方面，椎间盘切除术后在脊柱处于不同运动状态时应力分布状态发生改变，脊柱前屈时椎体前部应力最大；后伸时，后部及右侧前屈状态下最大应力在右侧。垂直压缩和旋转时，应力分布均匀。
结果表明，在所有运动状态下，人工椎间盘植入后椎体应力在3组中最小，且应力分布均匀。但与正常组相比，椎间盘切除术后椎体应力水平升高。总体而言，由于人工椎间盘植入对椎体产生的生物力学效应，用人工椎间盘重建椎间盘更为合理。
