腰椎融合联合Coflex系统术后邻近节段生物力学特性分析研究

Rigid fixation and spinal fusion is one of the most commonly used methods to stabilize the spine column after spinal cord decompression, but the loss of segmental motion may accelerate adjacent segment degeneration, which is more likely in multisegmental fixation. Recently, hybrid fixation has been designed to search for an alternative for multilevel fixation. Coflex is one type of interspinous dynamic fixation, which can stabilize the spine column without loss of segmental motion. Lumbar fusion combined with Coflex, as a transitional procedure from fused segment to mobile segment, may theoretically slow down progression of superior adjacent segment degeneration caused by fusion. To date, there have been few studies on the effect of adjacent segmental biomechanics resulting from such hybrid instrumentation. In this study, we try to combine ultrathin sheet plastination slice and finite element analysis, and establish an accurate finite element model followed by mechanical analysis. Mutual authentication will be made by biomechanical results from finite element analysis and specimen measurement. Measure the range of motion, intervertebral disc stress and facet joint stress of the adjacent segments after fusion combined with Coflex, and study the effect on adjacent segment after fusion combined with Coflex fixation, to provide new ideas for the treatment of doublesegmental and multisegmental lumbar degenerative disease.

融合固定术是腰椎减压术后稳定脊柱的常用方法之一，但固定节段活动度的丧失可能会加速邻近节段的退变，这在多节段融合固定中更为常见。近年来，为了寻求多节段融合术的替代固定方法，混合固定应运而生。Coflex是一种棘突间动态稳定系统，可以在稳定脊柱的同时保留植入节段的活动度。腰椎融合固定联合Coflex动态固定作为从融合节段向活动节段过渡的一种方法，理论上可以延缓多节段融合固定带来的邻近节段退变加速的问题，但目前尚缺乏关于该混合固定方式对邻近节段生物力学特性影响的研究。本研究拟结合薄层塑化切片技术及有限元方法，精确构建腰椎的三维有限元模型，进行力学分析，并与实验标本生物力学测试结果相互验证，测量腰椎融合联合Coflex动态固定系统术后邻近节段的活动度、椎间盘应力和双侧小关节内应力等，研究该混合固定方式对邻近节段生物力学特性的影响，为处理双节段乃至多节段腰椎退行性疾病提供新的思路。

融合固定术是腰椎减压术后稳定脊柱的常用方法之一，但固定节段活动度的丧失可能会加.速邻近节段的退变，这在多节段融合固定中更为常见。本研究采用有限元方法，精确构建腰椎的三维有限元模型，进行力学分析，并与实验标本生物力学测试结果相互验证，测量腰椎融合联合Coflex动态固定系统术后邻近节段的活动度、椎间盘应力和双侧小关节内应力等，研究该混合固定方式对邻近节段生物力学特性的影响，为处理双节段乃至多节段腰椎退行性疾病提供新的思路。本研究首次基于脊柱矢状位平衡状态的Roussouly分型系统对Coflex动态固定系统的作用进行研究，并发现Coflex对Roussouly1型脊柱效果不佳，而对Roussouly2型及4型效果尚可，Roussouly3型整体变化不大。而Topping-off技术能够使邻近节段运动能力增强，有助于提高脊柱的生物力学性能。