Zheng Sheng-Nai, Yao Qing-Qiang, Wang Li-Ming, Hu Wen-Hao, Wei Bo, Xu Yan, Zhang Dong-Sheng
Department of Orthopaedic Surgery, Nanjing Medical University Nanjing Hospital, Nanjing, Jiangsu 210029, P.R. China.
Exp Ther Med. 2013 Dec;6(6):1423-1430. doi: 10.3892/etm.2013.1313. Epub 2013 Sep 26.
This study aimed to optimize the design and application of semi-constrained integrated artificial discs (SIADs) using a finite element (FE) analysis following implantation, wherein the zygapophysial joints of the segment were biomechanically reconstructed. An FE model of the L4-L5 segment was constructed. Variations in the stresses on the discs and zygapophysial joints were observed during 5° anteflexion, 5° extension and 5° rotation under the 400-N applied axial load. Stresses and load translation analyses of the discs and zygapophysial joints were conducted during anteflexion, extension and rotation under the 400-N applied axial load. Following implantation of the lumbar segments, the stresses on the SIAD zygapophysial joints were not significantly different from those of physiological discs during anteflexion, and these were both marginally greater compared with those of non-constrained artificial discs (NADs). During extension, the increase in the stress on the SIAD zygapophysial joints was less than that on NAD zygapophysial joints. Stresses on the NAD zygapophysial joints were higher than those on SIAD and physiological discs during rotation. The stress on the SIAD zygapophysial joints was not significantly different from that on physiological discs during rotation. For SIADs and NADs, the stresses on the zygapophysial joints and the displacements of the discs were greater compared with those of the physiological discs during extension. The SIADs affected the variations in the stresses on the implanted segment more than the NADs, and the SIADs protected the zygapophysial joints of the implanted segment to a higher degree than the NADs.
本研究旨在通过植入后有限元（FE）分析优化半约束一体化人工椎间盘（SIAD）的设计与应用，其中对该节段的关节突关节进行了生物力学重建。构建了L4-L5节段的有限元模型。在400 N轴向载荷作用下，观察了该椎间盘和关节突关节在5°前屈、5°后伸和5°旋转过程中的应力变化。在400 N轴向载荷作用下，对椎间盘和关节突关节在前屈、后伸和旋转过程中进行了应力和载荷传递分析。腰椎节段植入后，SIAD关节突关节在前屈时的应力与生理椎间盘的应力无显著差异，且两者均略高于非约束人工椎间盘（NAD）。在后伸过程中，SIAD关节突关节应力的增加小于NAD关节突关节。在旋转过程中，NAD关节突关节的应力高于SIAD和生理椎间盘。在旋转过程中，SIAD关节突关节的应力与生理椎间盘的应力无显著差异。对于SIAD和NAD，在后伸过程中，关节突关节的应力和椎间盘的位移均大于生理椎间盘。与NAD相比，SIAD对植入节段应力变化的影响更大，且SIAD对植入节段关节突关节的保护程度高于NAD。
