不同高度下复位床托治疗胸腰段压缩性骨折的有限元分析

发布时间：2019-03-09 19:18

【摘要】：目的：利用逆向工程的医学图像三维可视化技术及医学有限元分析法,借助MIMICS软件,建立T11-L3椎体三维有限元模型,在此模型基础上探讨单纯胸腰段压缩性骨折的受力机制,模拟复位床托的治疗过程,分析复位过程中骨折椎体不同部位的应力分布情况和位移改变,探讨骨折椎体最佳复位高度。方法：招募志愿者,对一名健康男性志愿者进行64排螺旋CT扫描,将数据以DICOM格式输出并光盘保存,导入到医学三维重建软件MIMI C S中进行处理,生成三维实体图形,确定单元类型,赋予材料属性。然后将实体模型导入到ANS YS12.0有限元软件中,生成胸腰段三维有限元模型。模型验证后,给予模型一定的边界约束,施加载荷,建立胸腰段压缩性骨折模型,分析椎体的应力分布,探讨胸腰段压缩性骨折的受力机制。利用胸腰段压缩性骨折的有限元模型,模拟复位床托复位的治疗过程。结果：1.建立的胸腰段三维有限元模型基本符合正常人体的生物力学特征,共包括58815个节点,227774个单元,可用于胸腰段的相关的生物力学研究。2.模型经过验证后有效,模拟复位床托的治疗过程,在复位过程中,脊柱胸腰段表现出不同的应力、应变分布规律,对阐述L1椎体压缩性骨折的受伤机制具有重要意义,为复位床托治疗胸腰段椎体压缩性骨折提供充分的理论依据,便于临床推广。结论：建立的胸腰段三维有限元模型包含T11-L3的五个椎体、4个椎间盘及相应韧带等结构。对模型施加载荷,力量由小到大,模型获得的运动范围由大到小,最后趋于稳定,表现出非线性力学行为。L1椎体压缩性骨折有限元模型的结构也表现出非线性力学行为。骨折模型在不同复位高度施加复位载荷后表现出了不同的复位效果,当复位高度为10cm时,受伤椎体各部位的力学特性最稳定,复位效果最好。
[Abstract]:Objective: to establish the 3D finite element model of T11-L3 vertebral body by using the 3D visualization technique of medical image and the finite element analysis method of medicine in reverse engineering, and to discuss the stress mechanism of simply thoracolumbar compression fracture on the basis of the three dimensional finite element model of T11-L3 vertebral body. The stress distribution and displacement changes in different parts of the fractured vertebral body during the reduction were analyzed, and the optimal reduction height of the fractured vertebral body was discussed. Methods: volunteers were recruited and a healthy male volunteer was scanned with 64-slice spiral CT. The data was output in DICOM format and saved on CD-ROM. The data were imported into the medical 3D reconstruction software MIMI C S for processing and three-dimensional solid graphics were generated. Determine the element type and assign material properties. Then the solid model is imported into the ANS YS12.0 finite element software to generate the three-dimensional finite element model of the thoracolumbar segment. After the validation of the model, a model of thoracolumbar compression fracture was established by applying certain boundary constraints and loading to the model. The stress distribution of the vertebral body was analyzed, and the stress mechanism of the thoracolumbar compression fracture was discussed. The finite element model of thoracolumbar compression fracture was used to simulate the treatment of reduction with bed support. Results: 1. The three-dimensional finite element model of thoracolumbar segment basically accords with the biomechanical characteristics of normal human body, including 58815 nodes and 227774 elements, which can be used in the biomechanical study of the thoracolumbar segment. 2. The model is effective after verification and simulates the treatment process of reduction bed. During the reduction process, the distribution of stress and strain in the thoracolumbar segment of the spine is different, which is of great significance to explain the injury mechanism of the compression fracture of the L1 vertebral body. It provides sufficient theoretical basis for the treatment of thoracolumbar vertebral compression fracture with reduction bed support, which is convenient for clinical popularization. Conclusion: the three-dimensional finite element model of thoracolumbar segment consists of five vertebrae, four intervertebral discs and corresponding ligaments of T11-L3. When the load is applied to the model, the force increases from small to large, and the range of motion obtained by the model changes from large to small, and finally tends to be stable, showing nonlinear mechanical behavior. The structure of the finite element model of L1 vertebral compression fracture also shows nonlinear mechanical behavior. When the reduction height is 10cm, the mechanical properties of the injured vertebral body are the most stable and the reduction effect is the best.
【学位授予单位】：湖南中医药大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687.3

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