腰椎内镜下髓核摘除术对不同退变程度邻近节段椎间盘生物力学影响的有限元分析

目的:探讨腰椎侧后路经皮内镜下髓核摘除术(percutaneous transforaminal endoscopic discectomy,PTED)对不同退变程度邻近节段椎间盘的生物力学的影响以及由该术式导致的邻椎病(adjacent segment diseases,ASD)发病风险.方法:选择成年健康男性志愿者...

Biomechanical affect of percutaneous transforaminal endoscopic discectomy on adjacent segments with different degrees of degeneration:a finite element analysis

Objective: To investigate the biomechanical affect of percutaneous transforaminal endoscopic discectomy(PTED) on adjacent segments with different degrees of degeneration and related risk of adjacent segment diseases(ASD) caused by this operation.Methods: A healthy male adult volunteer was selected,and the lumbosacral vertebra image data was obtained by CT scan,and the external contour of the bone structure was reconstructed. On this basis,the external contour of the bone structure was fitted by using the smooth curve in 3D-CAD software,and the complete three-dimensional finite element model of the non-degenerate L₃-S₁ segment and the degenerative models of the L₃-L₄ and L₅-S₁ segment were drawn forward. In L₄,L₅ segment simulating PTED surgery through the removal of right part of articular process and nucleus pulposus and anulus fibrosus. After PTED was simulated in the L₄-L₅ segment and the risk of ASD has been evaluated by six changes of biomechanical indicators in flexion,extension,left and right lateral bending,left and right axial rotation conditions.Results: In the finite element model without adjacent segmental disc degeneration,the annulus fibrosus von Mises stress and intradiscal pressure of the PTED model showed only a slight increase under most stress conditions,and a slight decrease in a few conditions,and there was no significant change trend before and after surgery. In the original degenerated adjacent segment disc model,the biomechanical indicators related to disc degeneration in the pre- and post-PTED model showed significant deterioration,leading to an increased risk of potential adjacent spondylopathy.Conclusion: PTED surgery will not lead to the significant deterioration of postoperative biomechanical environment of non-degeneration adjacent intervertebral discs,and the original degeneration of adjacent intervertebral discs is a important risk factor for ASD.