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[目的]运用三维有限元分析方法,对儿童肱骨髁上骨折外侧克氏针固定常见方式的稳定性进行对比评价,为临床固定方法的优化提供理论依据。[方法]选取1名健康发育儿童,使用螺旋CT对志愿儿童肱骨进行水平扫描,以Dicom格式文件储存所得的扫描图像。使用Mimics 13.1及3-matic 5.1数字化三维医学影像软件、ANSYS10.0有限元处理软件,建立儿童肱骨远端有限元模型。在此基础上进一步生成肱骨髁上骨折模型,将ProE 2.0软件中生成的克氏针模型导入骨折模型并装配,设定边界及载荷条件,进行三维有限元分析。予模拟侧方弯曲和扭转实验,分析不同外侧克氏针固定方式下骨折模型的最大位移值和转角值。[结果]成功建立了不同外侧克氏针固定的儿童肱骨髁上骨折模型,并予模拟力学实验。从侧方弯曲实验结果看,外侧3枚克氏针固定模型最大位移值为4.92 mm,明显小于其他模型,抗内翻稳定性最强;从扭转实验结果看,外侧3枚克氏针固定模型的最大转角值为1.29°,亦小于其他模型,抗扭转稳定性最强。[结论]肱骨髁上骨折外侧3枚克氏针分散固定的生物力学稳定性最强。临床上对肱骨髁上骨折闭合复位后肘关节肿胀明显、肱骨内上髁触摸不清的患儿,可行外侧3枚克氏针分散固定,达到稳定骨折断端的结果,且避免损伤尺神经,更降低了术后肘内翻畸形的发生。
[Objective] To compare and evaluate the stability of the common Kirschner wire fixation for supracondylar fractures of humerus in children by using the three-dimensional finite element analysis method, and provide a theoretical basis for the optimization of clinical fixation methods. [Method] A healthy developmental child was selected and the humerus of volunteer children was scanned horizontally by spiral CT. The scanned images were stored in Dicom format. Using Mimics 13.1 and 3-matic 5.1 digital three-dimensional medical imaging software, ANSYS10.0 finite element software to establish a finite element model of the distal humerus of children. On this basis, the model of supracondylar humerus fracture was further generated. The Kirschner wire model generated in ProE 2.0 software was introduced into the fracture model and assembled. Boundary and loading conditions were set and three-dimensional finite element analysis was performed. To simulate the lateral bending and torsion experiments, the maximum displacement and rotation angle of the fracture model under different lateral Kirschner wire fixation were analyzed. [Results] The model of supracondylar fractures of humerus has been successfully established in children with different Kirschner wire fixation and simulated by mechanical simulation. From the lateral bending test results, the maximum displacement value of the three Kirschner wire fixation models on the outer side is 4.92 mm, which is obviously smaller than other models and the anti-inversion stability is the strongest. From the results of torsion test, three Kirschner wire fixation models The maximum angle of rotation is 1.29 °, which is also smaller than that of other models. It has the strongest anti-torsion stability. [Conclusion] The biomechanical stability of 3 Kirschner wires distally in the lateral humeral supracondylar fractures is the strongest. Clinically, the humeral supracondylar fractures closed after the reduction of elbow swollen obvious, humeral epicondyle touch unclear children, viable three Kirschner wire decentralized fixation, to stabilize the broken ends of the fracture results, and to avoid damage ulnar nerve, But also reduce the incidence of cubitus varus deformity.