基于有限单元法的股骨干粉碎性骨折锁定板内固定优化仿真

Application of finite element analysis in LCP fixation for femur shaft comminuted fracture

目的研究粉碎性股骨干骨折采用锁定板内固定时选择不同螺钉位置固定情况下锁定板及螺钉最大应力情况。方法通过64层螺旋CT扫描采集27名健康志愿者左侧股骨数据并导入Mimics软件,建立骨骼3D模型并依据CT值为股骨赋材料属性。用三坐标测量仪扫描锁定板,并将生成的点云文件导入Geomagic Studio生成光顺曲面及实体文件;将股骨及锁定板文件导入有限元分析软件Abaqus进行装配,施加压力和扭矩载荷,并对锁定板及螺钉的应力分布进行求解。结果对于粉碎性股骨干骨折,在压力和力矩载荷作用下,不同螺钉位置组合时的锁定板及螺钉上应力峰值均出现在最内侧螺钉处,即最靠近骨折线处;并且随着最内侧固定螺钉外移,锁定板及螺钉上分布的应力峰值均逐渐增大。结论对于粉碎性股骨干骨折锁定板内固定,使用较多的螺钉固定可使螺钉及锁定板上的应力峰值减小,同时最内侧螺钉尽量靠近骨折端。

Objective To study the difference of maximum stress among different positions of screws in the treatment of femur shaft comminuted fracture by locking compression plate （LCP）. Methods The CT data of left femur from 27 healthy volunteers were collected and imputed into Mimics, where 3D model was built; Point-cloud file of LCP were collected and imputed into Geomagic Studio; then model of femur and LCP were assembled together and analysed in Abaqus by simulating pressure and torque load. Results For the comminuted femur shaft fractures, the maximum stress of LCP and screws were detected from the innermost screw and its corresponding hole, and it increased while the innermost screw moved towards outside. Conclusion For the comminuted femur shaft fractures, using more screws may lead to decrease of maximum stress on LCP and screws, and the innermost screw should be as near to the fracture as possible.