股骨骨折术后1年随访骨愈合模型的有限元分析

Finite Element Analysis of Femur Fracture Treated by Internal Fixation 1 year later

目的:对股骨骨折髓内钉术后1年骨愈合模型快速建模,通过有限元分析研究对比术前术后模型,通过术前判定内固定取出后骨折断端是否断裂。方法:运用Mimics、Geomagic Studio、Abaqus等软件采用快速个体化建模方法对股骨骨折髓内钉术后1年内固定取出术前后的多层螺旋CT数据进行快速建立模型,术前模型模拟剥除钢板后进行有限元分析,施加人体单腿站立时的静力载荷和约束,并将分析结果与术后模型进行对比,观察米塞斯应力分布情况、最大值及其所处部位。结果:按照材料属性进行区别显示米赛斯应力的最大值及最小值,在不同应力载荷下,手术前后各类型材料的米赛斯应力最大值及最小值部位相同,各类型材料中,最大值均没有位于骨折断端,不同方法的最大应力值部位相近,均在股骨中远端1/4交界处,手术前后应力分布基本相同。结论:采用个体化建模方法可以对骨折内固定取出前的骨愈合模型进行运算分析,快速预判术后是否导致骨折断端断裂。

Objective： To investigate the bone healing model of femur fracture would disrupt or not by finite element analysis, which were treated by intramedullary pin 1 year later and were dislodged the internal fixation. Methods： Depend on fast individual establishment, bone healing model of femur fracture were constructed based on data from multi-slice spiral CT as well as Mimics, Geomagic Studio and Abaqus. The intramedullary pin was removed by Boolean operation before fixation disloged. Loads were applied on each model to simulate one-leg-standing status. The distribution of von mises, maximum von mises and the location were observed. Results： According to 10 kinds of display groups based on material assignment, the node of maximum and minimum von mises were same before and after dislogement, and all node of maximum von mises were out of the fracture line. The maximum von mises＇ node were situated at bottom quarter of femoral. The distribution of von mises was same also. Conclusion： Depending on fast individual establishment, it can successfully judge the model of femur fracture would disrupt or not by finite element analysis in short time before dislodgment.