齿槽型人工髋关节骨应力分布的三维有限元分析

Three-dimensional Finite Element Analysis of Bone Stress Distribution around the Hip Joint Prosthesis with Stepped Stem

基于人体股骨CT数据,结合髋关节解剖形态学,建立了齿槽型人工髋关节置换医学装配模型,运用三维有限元分析(3D-FEA)方法,选择1.5倍体重(70 kg)生理载荷条件,计算分析了人工髋关节柄三角区表面不同齿槽结构及分布对周围骨应力的影响。结果表明:关节柄三角区齿槽结构改变了关节柄/骨界面的应力传导,有利于降低股骨近端的应力遮挡效应。凸齿结构的效果优于凹齿,近端1/3凸齿分布的关节柄对降低骨的应力遮挡效果最佳,更有利于减轻股骨近端骨质疏松,能有效提高人工髋关节的使用寿命。

Based on the CT data,a medical treatment FE model of hip joint prosthesis with stepped stem was rebuilt according the anatomy of the hip joint.Under the loads of 1.5 times standard body weight（70kg）,the mechanical behavior of the treatment model was calculated,and the influence of step structure and distribution for stepped stem on femur stress and stability of total hip replacement were analyzed by three-dimensional finite element analysis（3D-FEA）.The results show that the step structure changs the bone stress transmission on the interface of stepped stem and femur,and benefits to reduce stress-shielding in the femur.For the same distribution of step,the reduction of stress-shielding for raised stepped stem is better than that for concave stepped stem.The raised stepped stem of which the steps is distributed one of third part of the stem is of the best effect of reduction of stress shielding in all of the analysis models,and is a beneficial mechanical design to relieves osteoporosis or osteopenia of femur caused by stress-shielding and improve the reliability of it in clinic.