髋臼横断骨折后柱长/短钢板内固定的有限元建模及分析

FEM Modeling and Analysis of Transverse Fractured Acetabulum with Fixations of Posterior Column Long Plate and Short Plate

目的建立有效的髋臼横断骨折有限元模型,完成两种内固定方式的比较。方法利用Mimics 10.0中建立髋臼骨骨折的三维模型,在逆向工程Geomagic中进行相应处理后,在ANSYSWorkbench中生成短/长钢板固定模型,并进行加载分析。结果相同加载方式下,短钢板模型的最大位移、模型整体及髋臼窝处的最大应力和最大应变,均大于长钢板模型。另外,短钢板模型更容易错位失效。结论本文有限元模型能有效地反映骨盆应力分布,分析结果表明后壁钢板固定时,将钢板长度延伸至坐骨结节处能提供更大的稳定性。

Objective To establish a valid finite element model of the transverse fractured acetabulum and finish the analysis of inner fixation ways. Methods The three-dimensional image of the pelvis was reconstructed with the software Mimics 10.0 and was modified with the software Geomagic. Then the 3D model of fractured pelvis was imported into ansys workbench and was established after some operations. After that the integrated 3D finite element models of transverse fractured acetabulums were established, which were fixed with posterior column long and short plates respectively. Finally the vertical load pressure was exerted on the upper terminal plate of the pelvis with some constrainer, and the distribution of stress was analyzed. Results With same loads, the maximum total deformation, von-mises stress and von-mises strain of short plate were bigger than them of long plate. In addition, the model with short plate was easier to lapse. Conclusion It was indicated that the proposed model was stable and valid to contribute the stress of pelvis. For the fixation of transverse fractured acetabulum with a posterior plate, extending the plate to hucklebone tuber was considered more stable.