髋臼后壁骨折的三维有限元模型构建与应力分析  

Three-dimensional finite element model of the fracture of posterior acetabular wall： construction and stress analysis

作　　者：梅良斌[1] 王钢[1] 张美超[2] 任义军[1] 王瑞金[1] 

机构地区：[1]南方医科大学南方医院创伤骨科,广州510515 [2]南方医科大学医学生物力学实验室

出　　处：《中华创伤骨科杂志》2007年第5期456-459,共4页Chinese Journal of Orthopaedic Trauma

基　　金：广东省自然科学基金（04020455）

摘　　要：目的通过构建髋臼三维有限元模型，探讨髋臼在后壁不同面积骨折情况下应力分布的变化。方法通过对髋骨大体标本进行CT扫描，获取断层图像，利用Mimics软件重建三维模型；然后将模型导入FreeForm软件进行修饰处理，再以IGES格式导入有限元软件Ansys对各组成部分进行力学参数赋值，建立髋臼三维有限元模型。依次按后壁1／3、2／3、3／3骨折面积将模型进行拆分，模拟双足直立位进行加载，分析臼顶负重区、髋臼前壁和剩余后壁在各骨折状态下应力分布大小及改变。结果建立了髋骨三维有限元模型，共69440个节点，45209个单元。加载分析显示髋臼后壁骨折使臼顶负重区应力依次增加20％、26％、33％，以垂直方向应力最为显著；前壁应力依次降低22％、30％、35％；剩余后壁应力依次增加39％、47％、54％。结论构建髋臼三维有限元模型进行加载分析是一种较好的生物力学测试方法，具有较高的仿真度。后壁骨折明显改变了髋臼各部分的应力大小与分布。Objective To construct three-dimensional （3D） finite element models of the fracture of posterior acetabular wall and analyze the stress distributions in fractures of different degrees of fracture. Methods 3D models of acetabulum were constructed from CT images with Mimics software, modified with FreeForm software, and then divided into 3D finite element units with Ansys software. Mechanical parameters were used to construct 3D finite element acetabular models of 1/3, 2/3 and 3/3 fractures of posterior wall. The models were tested and their stress distributions compared. Results The constructed 3D finite element acetabular models were divided into 69 440 nodes and 45 209 units. The loading tests revealed that the 1/3, 2/3 and 3/3 fractures of posterior acetabular wall increased the stress at the weight-bearing dome by 20%, 26% and 33% respectively, with most significant increase in the perpendicular direction. By contrast, the stress at the anterior wall decreased by 22%, 30% and 35%, while the stress at the remaining posterior wall increased by 39%, 47% and 54% respectively. Conclusions The 3D finite element acetabular models can simulate the real anatomy and mechanic performance of the acetabulum clearly so that it can be used for biomechanical experiments. The posterior wall fractures alter the stress distribution at the acetabulum significantly.

关 键 词：髋臼 骨折 有限元法 生物力学 

分 类 号：R686[医药卫生—骨科学]