三维有限元法分析先天性脊柱侧凸冠状面腰骶段的柔韧性

发布时间：2018-05-24 13:02

本文选题：脊柱侧凸 + 有限元分析　；参考：《中国组织工程研究》2017年27期

【摘要】：背景:先天性脊柱侧凸患者脊柱运动单元发育存在缺陷,椎体活动柔韧性相对较差,在临床工作中发现此类患者冠状面腰骶段(L_4-S_1)的脊柱代偿能力和术后是否会出现不可自行代偿的躯干偏移存在一定关联。目的:建立正常人和先天性脊柱侧凸患者冠状面腰骶段不同柔韧性的三维有限元模型,通过比较3种模型在不同载荷下的形变、位移、应力和刚度等力学数值变化而完成有限元分析。方法:分别以1名正常人和术前冠状面腰骶段柔韧性不同(随访中是否发生不可代偿的躯干偏移)的2名先天性脊柱侧凸患者为建模样本,通过螺旋CT扫描获得腰骶段DICOM格式的图像数据,将其导入到三维重建软件MIMICS中,根据选取CT图像中各组织的灰度值不同,通过阈值来提取相应的组织,生成3D模型,并将通过GEOMAGIC进行简化处理后的腰骶段三维模型导入到有限元软件ABAQUS中进行不同载荷状态下的力学指标分析。结果与结论:①3种模型在受不同侧向力的情况下,最大应力分布区域都集中在L_4皮质骨前部,而最大位移分布区域主要集中在L_5上;②不可代偿性模型(随访中发生不可代偿的躯干偏移)和可代偿性模型(随访中发生可代偿的躯干偏移)在受不同侧向力的情况下,应力分布几乎没有变化,但可代偿性模型在同样载荷作用下会产生更大的位移变化,而且刚度也明显小于不可代偿性模型,即可代偿模型在受到同等力的作用下更容易变形;③结果提示,通过三维有限元模型可以完成对先天性脊柱侧凸冠状面腰骶段柔韧性的生物力学分析,而且生物力学结果也与作者的临床设想一致,即可代偿性先天性脊柱侧凸患者腰骶段椎体间角度变化的幅度更大,提示其腰骶段柔韧性更好。
[Abstract]:Background: congenital scoliosis patients have defects in the development of the motor unit of the spine and relatively poor mobility of the vertebral body. It was found that there was a certain correlation between the spinal compensatory ability of the coronal lumbosacral segment L _ (4-S _ 1) and the non-compensatory trunk deviation after operation. Objective: to establish three dimensional finite element models of different flexibility of coronal lumbosacral segment in normal subjects and congenital scoliosis patients, and to compare the deformation and displacement of the three models under different loads. The finite element analysis is completed because of the numerical variation of stress and stiffness. Methods: two patients with congenital scoliosis, one normal person and two patients with different preoperative coronal lumbosacral flexibility (whether irreparable trunk deviation occurred during follow-up), were selected as model samples. The image data of lumbosacral segment DICOM format were obtained by spiral CT scanning and imported into the 3D reconstruction software MIMICS. According to the different gray values of each tissue in the CT image, the corresponding tissue was extracted by threshold value, and the 3D model was generated. The three dimensional model of lumbosacral segment which was simplified by GEOMAGIC was introduced into the finite element software ABAQUS to analyze the mechanical indexes under different loading conditions. Results and conclusion under different lateral forces, the maximum stress distribution region of the 13 models was concentrated in the anterior part of the cortical bone, while the maximum displacement area was mainly concentrated in L5. (2) the non-compensatory model (irreparable trunk offset) and the compensable model (compensable trunk offset during follow-up) had little change in stress distribution under different lateral forces. However, the compensability model will produce greater displacement change under the same load, and the stiffness is obviously smaller than that of the irreplaceable model. The result shows that the compensatory model is more easily deformed under the same force. The biomechanical analysis of the flexibility of lumbosacral segment on the coronal surface of congenital scoliosis can be completed by using the three-dimensional finite element model, and the biomechanical results are consistent with the author's clinical assumptions. The angle of lumbosacral vertebrae in the patients with compensatory congenital scoliosis is larger, indicating that the lumbosacral segment is more flexible.
【作者单位】：中国医学科学院北京协和医院骨科;河北工业大学机械学院;天津医科大学医学影像学院;Radiology
【基金】：天津市自然科学基金(17JCZDJC32500)~~
【分类号】：R687.3

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