基于有限元模型的人体损伤脊柱的动态特性分析

为了研究在全身振动情况下损伤脊椎对其相临组织部件的影响,建立了一个腰椎L3-L5段的三维非线性有限元模型.研究对脊椎给予了几种损伤假设,如小关节切除、去髓核和后部结构切除等,并对这几种损伤情况进行了有限元瞬态分析.结果表明,腰椎在振动过程中不仅存在垂直方向的振动还伴随有仰俯运动.脊椎小关节可以限制腰椎仰俯运动的幅度以保护纤维环后部免受大的拉伸和高应力的危害.椎间盘去髓核会导致纤维环上高应力的产生和椎间盘鼓胀增大.在振动过程中,小关节的切除同样可以加速椎间盘的退化.

FEM-Based Dynamic Analysis of Injured Human Spine

To investigate the influence of injured lumbar spine on its adjacent components under whole body vibration, a nonlinear three-dimensional finite element model of lumbar spine segments L3-L5 was developed. Several injury conditions of spine components were assumed, such as facetomy, denucleation and removal of posterior elements, and the dynamic finite element analyses were carried out to those injury conditions. The results show that the lumbar spine exhibits not only the vertical vibration but also the flexion-extension motion during vibration. The facet joints can limit the amplitude of flexion-extension motion of lumbar spine so as to protect the posterior region of annulus from large strain and stress during vibration. The disc denucleation will lead to high stress and bulge of intervertebral discs. The facetomy may exacerbate the degeration of intervertebral disc in the process of whole body vibration.