尖顶距对股骨粗隆间骨折动力髋螺钉内固定稳定性的相关有限元分析

Effects of tip-apex distance on the stability of dynamic hip screws for internal fixation of intertrochanteric fracture

目的 以有限元分析比较相同生理载荷下,股骨粗隆间骨折动力髋螺钉（DHS）内固定不同安放位置的尖顶距对骨折稳定性的影响,供临床参考.方法 计算健康老年志愿者DHS内固定三维有限元模型的尖顶距在22～34 mm范围内的力学特征,综合评价髋螺钉不同安放位置的固定效果.结果 随着DHS尖顶距的不断减小,股骨的Von-Mises应力、位移逐渐减小.尖顶距为（22 ～28） mm组应力、位移最小.结论 髋螺钉尖顶距在22 ～34 mm范围内越小,DHS内固定对骨折的稳定性越好.

Objective To investigate the effects of tip - apex distance （TAD） on the stability of dynamic hip screws （DHSs） for internal fixation of intertrochanteric fractures through finite element analysis. The DHSs were exposed to the same physiological load. Methods Healthy elderly volunteers were included to undergo spiral CT scanning on the femur for building a 3 - D finite element model. Mimics 13.0 and Abaqus 6.10 software were adopted to establish an internal fixation model of intertrochanteric fractures, where DHSs were in different locations. Then, the effects of TAD on the sta- bility of DHSs were assessed. Results With the decrease of TAD, the femur presented shrinkages in Von Mises Stress and displacement. 22 - 28 mm of TAD could cause the minimal values of the Stress and displacement. Conclusion The stability of the implant increases when the value of TAD shrinks within a range of 22 to 34 ram.