人工股骨头置换治疗严重股骨转子间骨折的有限元分析

目的　建立股骨转子间骨折、人工关节假体的三维数字模型，应用有限元对人工股骨头置换术后的股骨应力分布进行分析，评价置换术后的初始稳定性。 方法　利用螺旋CT对志愿者的左侧股骨进行断层扫描获取图像数据，经Mimics软件和Unigraphics建模软件处理，重建股骨三维模型。在此基础上，建立股骨转子间骨折、标准柄股骨假体三维实体模型，最后利用有限元分析软件Ansys10.0建立人工股骨头置换术治疗股骨转子间骨折的三维有限元模型，并对该模型进行生物力学分析。 结果　应力分析显示：正常股骨的应力由近端向远端逐渐上升，并于中下段达到最高。同时人工股骨头假体的应力集中于中段，与正常股骨的应力变化基本一致。人工股骨头置换没有改变股骨总体的应力模式，股骨距部位未见明显的应力集中区，依然是由近端向远端逐渐增加，应力峰值区域亦于全长股骨的中下段。 结论　标准柄人工股骨头置换治疗股骨转子间骨折不会引起股骨应力分布的明显改变，可以获得重建后的初期稳定。

A finite element stress analysis of severe intertrochanic fractures treated with artificial femoral head replacement

Objective　To investigate the stress distribution of the femur after artificial femoral head replacement in patients with comminuted intertrochanteric fracture．Methods　A volunteer's left femur image data was obtained by spiral CT tomography．Then，the three-dimensional model of the femur was reconstructed with Mimics and Unigraphics modeling software．Based on the above analysis，we established three-dimensional models of comminuted intertrochanteric fracture，short stem prosthesis. Finally, we established the three-dimension finite element model of these materials with software Ansys10.0, and carried out finite element analysis to the model in biomechanics．Results　The stress distribution of the femur after standard stem prosthetic replacement did not change significantly．There was no significant stress concentration zone in the reconstruct calcar femorale. Conclusion The stability of prosthesis for intertrochanteric fractures after standard stem prosthesis joint replacement is good, and the artificial joint isstable under normal load.