摘要
背景:临床采用Ilizarov骨外固定器胫骨延长时,准确、及时预测胫骨延长过程中截骨端出现的空间移位情况比较困难。目的:通过有限元分析软件(ANSYS)加载轴向负荷并模拟采集Ilizarov骨外固定器胫骨延长的三维模型,建立一种截骨端轴向相对位移的计算方法,为临床监测截骨延长质量提供理论依据和调整方法。方法:选择1例Ilizarov骨外固定器(四杆偏心分布)行小腿延长的患者进行CT扫描,dicom数据导入Mimics建立3D模型,预处理后在Solidworks优化建模。设定胫骨断端延长20 mm,根据远截骨单位末端冠状位水平偏移量(0,4,7,10,13,16 mm)分别建立模型,采用ANSYS静力学模块进行加载(胫骨远端垂直地面200 N)和有限元分析,根据骨外固定器轴向各支撑杆载荷数据计算出合力坐标位置,计算其与胫骨截骨近端坐标的偏差大小和方向。结果与结论:(1)远截骨单位末端冠状位水平偏移量(0,4,7,10,13,16 mm)不同模型施加载荷后,合力坐标位置水平计算偏移量分别为0.8,2.9,5.4,8.3,11.8,14.9 mm,计算误差分别为0.8,1.1,1.6,1.7,1.2,1.1 mm;(2)当计算误差≥1.7 mm时合力坐标可判断截骨远端单位位移方向,为临床外固定调整提供量化依据;根据合力坐标系可以计算外固定调整方法并矫正畸形;(3)综上,通过Ilizarov骨外固定胫骨延长模型的有限元分析,建立数学模型可用于截骨远端单位轴向偏移量计算,计算误差≥1.7 mm合力坐标可判断截骨远端单位位移方向,指导临床Ilizarov外固定调整,避免骨延长过程中的并发症。
BACKGROUND： It is difficult to predict the spatial displacement accurately and timely during the elongation of tibia in the osteotomy by using Ilizarov external fixation. OBJECTIVE： To load axial load, simulate the acquisition of three-dimensional（3D） models with Ilizarov external fixation by finite element analysis software（ANSYS）, establish the calculation method of the axial relative displacement, and provide theoretical basis and adjustment method for clinical monitoring the quality of osteotomy length. METHODS： The 3D model was built in Mimics by using CT scan of the bone-Ilizarov external fixator（four-bar eccentric distribution） in a patient. The model was optimized in Solidworks. The tibia elongation was assumed to be 20 mm. The model was established according to the horizontal displacement of distal fragment in coronal sections（0, 4, 7, 10, 13 and 16 mm）. The axial force of Ilizarov external fixator was set to 200 N and it was analyzed by finite element method through ANSYS static module. The coordinate position of net force was calculated according to the load data, and the magnitude and direction of the tibial osteotoma were calculated. RESULTS AND CONCLUSION：（1） The models of different horizontal displacement of the distal fragment in coronal section（0, 4, 7, 10, 13 and 16 mm） were loaded. The horizontal offset（0.8, 2.9, 5.4, 8.3, 11.8, 14.9 mm） and errors（0.8, 1.1, 1.6, 1.7, 1.2, 1.1 mm） were calculated respectively.（2） When the calculation error was not less than 1.7 mm, the displacement direction of the distal fragment could be determined, which provided a quantitative basis for clinical treatment; it calculated the external fixed adjustment method and corrected the deformity.（3） In conclusion, the model of Ilizarov external fixation is analyzed by using finite element method, and the mathematical model is established to calculate the axial offset of the distal fragment. When the calculation error is not less than 1.7 mm, the distal fragment displaceme
作者
李慨
谭琪
张弢
侯书军
刘彦士
张兴鹏
Li Kai;Tan Qi;Zhang Tao;Hou Shu-jun;Liu Yan-shi;Zhang Xing-peng(School of Mechanical Engineering,Hebei University of Technology,Tianjin 300130,China;Department of Orthopedics,Tianjin Hospital,Tianjin 300211,China)
出处
《中国组织工程研究》
CAS
北大核心
2018年第23期3675-3680,共6页
Chinese Journal of Tissue Engineering Research
