儿童肱骨远端有限元模型的建立及力学分析

Establishment of the finite element model of distal humeral and its biomechanical analysis

目的建立儿童肱骨远端有限元模型,并模拟肱骨轴向受力状态下应力分布,为肱骨的生物力学研究提供数值分析模型。方法通过CT扫描正常儿童右侧肱骨,获得连续断层图片,导入mimics13.1医学建模软件进行网格划分、材料属性赋值,生成有限元模型,应用有限元分析软件ANSYS10.0,约束边界条件,模拟肱骨轴向受力状态进行加载,得出肱骨远端有限元模型上的应力分布。结果建立的肱骨远端有限元模型节点共50364个、四面体单元29951个。肱骨在轴向载荷状态下应力集中主要位于髁上区,且尺侧应力集中现象较桡侧明显。结论应力分析结果解释了肱骨骨折好发于髁上区的原因,髁上区尺侧骨质的高应力是肱骨髁上骨折致肘内翻的基本生物力学因素。

Objective To establish a three dimensional finite element model of normal distal humerus and calculate the stress distribution on the humerus under the axial load,so as to provide a numerical model for analysis of biomechanical behaviors.Methods The right humerus of a healthy normal child was scanned by CT and serial sections were obtained.The CT images were analyzed using the ANSYS10.0 software to create the model through a serial steps including meshing,assigning the material attribution,restricting the freedom and simulating axial loading.The result of stress distribution was obtained.Results The established model had 50 364 nodes and 29 951 tetrahedral units.The stress mainly concentrated on the supracondylar humerus under axial loading.And the stress on the ulnar side was obviously higher than that on the radial side.Conclusion The stress distribution analysis explains the reason why supracondylar humerusis prone to fracture.The high stress distribution on the ulnar side is the basic mechanical factor for cubitus varus.