不同角度螺钉固定股骨颈骨折并发转子下骨折风险的生物力学分析

A Biomechanical Study of Risk of Subtrochanteric Femur Fracture after Different Angle Fixation for Adductive Femoral Neck Fracture

目的通过有限元方法对内收型股骨颈骨折的不同角度空心加压螺钉固定技术进行对比评价,判断何种技术更易发生转子下骨折,为临床应用提供理论依据。方法以内收型股骨颈骨折为研究对象建立有限元模型,模拟单腿站立时的受载和垂直力加载2种情况,对倒三角构型不同角度置钉技术分别进行有限元计算。结果第3模型在股骨干张力侧的最大Von-Mis-es应力明显高于其他模型,其他模型张力侧应力的差别都较小。结论倒三角构型时,单枚远钉低角度固定与传统高角度固定时发生转子下骨折的风险差别不大,只有三钉同时低角度固定时发生转子下骨折的可能性最大,建议临床避免低角度多钉固定。

Objective To compare different angle internal fixation for treatment of the adductive femoral neck fracture with cannulated compression screw with the finite element method, and evaluate the risk of subtrochanteric fracture of the complication of the internal fixation, and find out the rational fixation manner to guide clinical practice. Methods With the method of finite element analysis （FEA）, the model was set up according to the adductive femoral neck fracture and the biomechanical features of the different angle fixations with three screws in an inverted triangular configuration were compared. The model of standing on one leg was simulated as the load situation and the vertical force to bending was also loaded. Results The third model was higher in the best Von- Mises stress than other models. It was less different among other models. Conclusion It＇ s most possible to cause subtrochanteric femur fracture in low - angle placement with all of three screws.