锁骨三维有限元模型的建立及生物力学分析

目的:建立正常锁骨有限元模型,并模拟锁骨轴向受力状态下应力分布及应变特征,为锁骨的生物力学研究提供数值分析模型.方法:通过CT扫面正常成年男性右侧锁骨,获得连续断层图片,导入Simpleware医学建模软件生成实体模型后,应用通用有限元分析软件ANSYS 10.0,进行网格划分、材料属性赋值生成有限元模型.约束边界条件,模拟锁骨轴向受力状态进行加载,得出锁骨有限元模型上的应力分布与应变结果.结果:建立的锁骨有限元模型节点共62 182个、四面体单元40 878个.锁骨在轴向载荷状态下应力集中主要位干锁骨干中1/3区域,且下表面应力集中现象较上表面明显.结论:应力分析结果解释了锁骨骨折好发于中1/3的原因,并且发现主要应力集中于下表面,锁骨产生断裂的弯矩位于冠状面,提示临床内固定治疗锁骨中段骨折时,钢板放置于上表面能有效抵抗产生的弯矩,避免内固定失败.有限元分析法可较好分析锁骨的生物力学特点.

Three dimensional finite element modeling of clavicle and the related biomechanics analysis

Objective:To establish a three dimensional finite element model of normal clavicle and calculate the stress and strain distribution on the clavicle under the axial load,so as to provide a numerical model for analysis of biomechanical behaviors.Methods: The right clavicle of a healthy normal male was scanned by CT and serial sections were obtained.Then the CT images were fed into the Simpleware and ANSYS 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 and response of the model was obtained.Results: The established model had 62 182 nodes and 40 878 tetrahedral units.The stress mainly concentrated within the middle 1/3 part of the clavicle under axial loading,and the stress on the inferior surface was obviously higher than that on the superior surface.Conclusion: The stress distribution analysis explains the reason why the middle 1/3 region of clavicle is prone to fracture.The stress mainly focuses on the inferior surface and the bending movement leading to clavicle fracture is located on the coronal plane,indicating that placement of plate in the superior surface can effectively balance the bending movement and avoid fixation failure during internal fixation of middle segment clavicle fracture.In a word,finite element analysis can be used to effectively investigate the biomechanic characteristics of clavicle.