BACKGROUND: The biomechanics of cervical spine is complicated. It is an important way to select the appropriate biomechanical model and research method so as to explore the diagnosis and evaluation mechanism of cervical spine injury and prognosis judgement.OBJECTIVE: To discuss the alternation of cervical biomechanics after the degeneration of cervical disc and the influence of degeneration on cervical stability.METHODS: (1) A three-dimensional finite element model of cervical spine was established from the CT scan images of cervical spine of a healthy male volunteer, Solid-Works2015, HyperMesh and ANSYS11.0. We created a cervical three-dimensional finite element model. To simulate the degenerative disc by modified the mechanical characters and height of the disc model, we observed the biomechanics of the impact on the cervical spine (the range and the stress on intervertabral disc).RESULTS AND CONCLUSION: (1) The entire model with a total of 97705 nodes and 372896 elements. Ligament and joint capsule were also constructed. Face to face contact element was used in the facet joint, with complete structure and high accuracy of measurement of spatial structure. (2) The range of motion of cervical spine increased during degeneration compared with normal cervical segments (P < 0.05). (3) Intervertebral disc degeneration caused angle increase at disc and motion segment. Osteophyte formed on vertebral edge. Intervertebral disc degeneration caused cervical instability. Simultaneously, instability increased the disc degeneration.%背景:颈椎的生物力学表现较为复杂,选择合适的生物力学模型和研究方法是探求颈椎损伤的诊断评估机制和治疗预后判断的重要途径.目的:椎间盘退变后颈椎生物力学变化及对稳定性的影响.方法:①以一健康男性志愿者的颈椎为研究对象,利用CT扫描成像、CAD造型软件Solid-Works2015、HyperMesh软件、ANSYS11.0软件,建立全颈椎正常有限元模型,椎间盘高度降低合并严重退变有限元模型,分析其对颈椎的生物力学指标运动范围和椎间盘应力的影响.结果与结论:①整个模型共有97705个节点和372896个单元组成,远远超过了以前所建立的模型的单元数与节点数,并建立了韧带、关节囊等组织结构,而且在关节突关节等处采用了面-面接触单元,结构完整,空间结构的测量准确度高;②颈椎间盘退变时颈椎的运动范围及受力与正常颈椎节段相比均增加,并在统计学上有差异(P<0.05);③椎间盘退变引起椎间盘及运动节段的角度增加,椎体边缘可形成骨赘;椎间盘退变引起颈椎不稳,同时不稳又加重椎间盘退变.
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