外侧壁破裂股骨粗隆间骨折三种内固定有限元分析

A finite element analysis on three kinds of internal fixation for femoral intertrochanteric fracture with lateral wall fracture

摘要:

［目的］ 比较三种内固定外侧壁破裂型股骨粗隆间骨折的力学特性。［方法］ 自 1 名志愿者采集股骨 CT 图像，在 Mimics14. 0、Geomagic Studio、CERO3.0、Hypermesh13.0 软件处理，分别构建外侧壁破裂型股骨粗隆间骨折的 PFNA、PFNA 张力带和锁定钢板内固定模型。在 Abaqus6.12 中加载，分析内固定及骨折端应力和位移变化。［结果］ 三种内固定模式的 Von Mises 应力由大至小依次为颈干交界>股骨头区>骨折区，差异有统计学意义（P<0.05）。股骨头区 Von Mises 应力由大至小依次为 PFNA>PFNA 张力带>锁定钢板，差异有统计学意义 （P<0.05）；骨折区 Von Mises 应力三组间差异均无统计学意义 （P> 0.05）；颈干交界区 Von Mises 应力由大至小依次为 PFNA>锁定钢板>PFNA 张力带，差异有统计学意义（P<0.05）三种固定物骨折端位移由小至大依次为 PNFA 张力带<锁定钢板 。［结论］PFNA联合张力带固定治疗外侧壁破裂型股骨粗隆间骨折，能够减小应力和位移，有利于骨骼端稳定。

Abstract:

[Objective] To compare the mechanical properties of three kinds of internal fixation for femoral intertrochanteric fractures with lateral wall fracture. [Methods] The CT images of femur were obtained from a volunteer and processed by MIMICS14.0, Geomagic Stu- dio, CERO3.0, Hypermesh13.0 software to create the models of proximal femoral nail anti- rotation (PFNA) , PFNA enhanced by tension band and locking plate as internal fixation fore femoral intertrochanteric fractures with ruptured lateral wall respectively. The Von Mises stress and displacement of the implant and fractures were analyzed by using Abaqus6.12. [Results] All the Von Mises stresses of the three internal fixation modes were in descending order as the neck-trunk junction ＞ femoral head ＞ fracture site, with statistically significant dif- ferences (P＜0.05) . The Von Mises stress in femoral head was in descending order as PFNA ＞ PFNA-tension band ＞ locking plate with a statistically significant difference among them (P＜0.05) , whereas which proved not significantly different in the fracture site among the three groups (P＞0.05) , and were significantly ranked up-down in neck- trunk junction as PFNA ＞ Locking plate ＞ PFNA-tension band (P＜0.05) . Conversely, displacements of fracture ends were significantly arranged down- up in order of PNFA- tension band ＜ locking plate ＜ PFNA (P＜0.05) . [Conclusion] PFNA enhanced by tension band fixation does reduce the stress and displacement of femoral inter- trochanteric fracture complicated with lateral wall fracture, which is beneficial to the stability of fracture ends.