基于有限元法的Vancouver B1型股骨假体周围骨折内固定力学分析

目的 基于有限元方法,对Vancouver B1型股骨假体周围骨折内固定后的稳定性及生物力学状态进行分析研究.方法 收集30名中老年健康志愿者左侧股骨CT图像数据以及股骨假体、锁定钛板的外形数据并进行三维重建.模拟人工髋关节置换术后假体周围骨折锁定板内固定手术,近端分别采用钛缆捆扎、锁定螺钉单层皮质固定及两者组合,施加模拟完全负重及部分负重的载荷,观察最大位移及峰值应力情况.结果 对于近端钛缆捆扎与锁定螺钉单层皮质固定两种方式,在模拟完全负重及部分负重压力载荷作用下的骨折位移,锁定板、假体及股骨上的应力峰值差异均无统计学意义,也即钛缆捆扎和锁定螺钉单层皮质固定后生物力学状态无明显区别.但若将两者组合使用,则可增加内固定稳定性,并且降低锁定板应力峰值,与单独使用两种内固定方式的结果差异均有统计学意义(P＜0.05或P＜0.01).结论 对于Vancouver B1型股骨假体周围骨折切开复位锁定板内固定手术,钛缆捆扎结合锁定螺钉单层皮质固定是首选的内固定方式.

Finite element-based mechanical analysis of internal fixation for Vancouver type B1 periprosthetic femoral fractures

Objective: To research the biomechanics status and stability after internal fixation of Vancouver type B1 periprosthetic fractures using the finite element analysis method. Methods: The CT data of left femur from 30 elderly healthy volunteers, as well as outline data of femur prosthesis and locking compression plate were collected. Three different types of internal fixation method for Vancouver type B1 periprosthetic fracture were simulated. Different loads referred to full and partial weight bearing were applied. Then the maximum Von Mises stress and displacement were observered. Results: There was no significant statistically difference between cable cerclage fixation and single-cortical locking screw fixation under full and partial weight bearing load. But significant statistically difference could be found if they were combined together, that is, less displacement and smaller maximum Von Mises stress could be achieved. Conclusion: In the treatment of Vancouver type B1 periprosthetic fracture, combination of cable cerclage and single-cortical locking screw should be recommended as preferred internal fixation method.