目的:分析假体植入带来的力学变化导致远端微动的原因,以利于进一步对假体设计和选材及假体临床效果等多因素进行理论分析.方法:通过数学力学推导,假设股骨和假体柄为完全结合的同心圆柱体,建立了一个相对完善的界面应力传递理论模型,获得了界面剪切应力和径向应力随Z位置变化的分布.结果:界面最大的剪应力发生在z＝0处,即股骨颈的截面上,当z＞0.1 m时剪应力非常小,即股骨柄远端剪应力非常小;界面的径向应力随股骨柄长度Z的增加而加大,当z＞0.05 m时,径向应力几乎不变,即股骨柄远端的径向应力大.结论:股骨假体远端微动由径向应力引起.
Objective: To investigate possible causes of micromotion in distal femoral prosthesis. Methods: Based on the assumption that the femur and prosthesis were considered as concentric cylinders with completely bonded interface,a theoretical mode1 simulating the interfacia1 stress transfer was established.The distributions of the interfacia1 shear and radial stresses with the changing of z were obtained through mathematics and mechanics deducing. Results: The maximum interfacial shear stress occured at the position of z＝0,namely,the cross section of the femur neck.The interfacia1 shear stress sharply decreased with the increasing of z and came to nearly zero at the range of z＞0.1 m.While the interfacial radial stress increased with the increasing of z,at the range of z＞0.05 m it was constant and reached the maximum. Conclusion: The micromotion in distal prosthesis is caused by the interfacial radial stress.
董文伟;俞学中;郭乙木. 股骨假体远端微动的原因分析[J]. 浙江大学学报（医学版）, 2010, 39(2): 193-197.