不同型号配对固定平台型膝关节假体生物力学有限元分析研究  

Finite element analysis of fixed-bearing knee prosthesis with different size of femur and tibia parts

作　　者：刘志宏[1] 刘利[2] 韦林[2] 冯建民[1] 邓廉夫[1] 沈宇辉[1] 

机构地区：[1]上海市伤骨科研究所,上海交通大学医学院附属瑞金医院骨科,200025 [2]同济大学航空航天与力学学院,上海200092

出　　处：《国际骨科学杂志》2012年第5期322-325,共4页International Journal of Orthopaedics

基　　金：上海市自然科学基金(10ZR1427800)

摘　　要：目的针对组配式固定平台型膝关节假体在临床使用中为适应骨骼解剖形态,经常出现股骨和胫骨侧假体不同型号配对情况,采用有限元分析方法分析不同配对假体接触表面的应力变化,了解目前临床上常用的膝关节假体不同型号配对是否具有潜在风险。方法选择美国DePuy公司PFC Sigma固定平台型膝关节假体为研究对象,选用股骨侧3号钴铬合金假体,胫骨侧2.5号、3号、4号钛合金金属托及对应尺寸的10 mm厚度聚乙烯垫片。实验组:股骨侧3号假体选配胫骨侧2.5号假体(3/2.5配对)或4号假体(3/4配对);对照组:3号股骨假体对应3号胫骨侧假体(3/3配对)。两组分别构建计算机有限元模型后,模拟双腿站立、平地行走、上楼梯情况下,对膝关节活动处于0°、10°、20°、30°、45°、60°、75°夹角时最大等效应力进行有限元分析,比较实验组与对照组间最大等效应力差异。结果实验组(3/2.5配对或3/4配对)最大等效应力高于对照组(3/3配对)。其中模拟双腿站立时,3/3配对与3/2.5配对最大等效应力无显著差异(P>0.05),3/3配对与3/4配对最大等效应力有显著性差异(P<0.05);模拟平地行走时,3/3配对与3/2.5配对、3/4配对应力值在0°～75°范围内各角度之间差异均有统计学意义(P<0.05);模拟上楼梯时,3/3配对与3/2.5配对、3/4配对应力值在0°～30°范围内各角度之间差异均有统计学意义(P<0.05),45°～75°范围内各角度之间差异均无统计学意义(P>0.05)。结论实验组(3/2.5配对或3/4配对)假体型号不完全匹配,假体接触面最大等效应力在不同膝关节活动角度和不同运动状态时增高,可能增加聚乙烯垫片磨损风险。Objective In order to fit the anatomical bone form, different size of femoral and tibial part of fixed bearing modular knee prosthesis are often used. This study investigates contact stress of different matching groups by finite element analysis （FEA）, with the aim of learning the potential risks of different matching groups of knee prosthesis. Methods The size 3 cochrome femoral prosthesis, size 2. 5, 3 and 4 titanium tibial tray and 10 mm polyethylene insert of Depuy PFC Sigma fixed bearing knee prosthesis was selected for study. Experimental group： size 3 femoral prosthesis with size 2.5 （3/2. 5） and 4 （3/4） tibial prosthesis. Control group： size 3 femoral prosthesis with size 3 tibial prosthesis （3/3）. Finite element models were constructed respectively in two groups. Max. equivalent stress of simulative standing, flat floor walking, walking upstairs with knee flexion of 0°, 10°, 20°,30°,45°,60°and 75°were studied. The difference of equivalent stress between experimental group and control group was compared. Results The Max. equivalent stress of experimental group （3/2.5 or 3/4） was higher than that of control group （3/3）. In the simulative standing mode, there was no significant difference between 3/3 and 3/2. 5 pairing （P〉0.05） and there was significant difference between 3/3 and 3/4 pairing （P〈0. 05）. In the simulative flavfloor walking mode, there was significant difference between 3/3, 3/2. 5 and 3/4 pairing among different angles from 0°to 75°（P〈0. 05）. In the simulative walking upstairs mode, there was significant difference between 3/3, 3/2. 5 and 3/4 pairing among different angles from 0°to 30°（P〈0. 05）, yet no significant difference was found within the range of 45°to 75°（P〉0. 05）. Conclusions The Max. equivalent stress of contact area at different motion angle and status of experimental group （3/2. 5 or 3/4） increases due to different sizes of femoral and tibial prosthesis, which may lead to increased wearing of polyethylene

关 键 词：人工膝关节 生物力学 有限元分析 等效应力 

分 类 号：R687.4[医药卫生—骨科学]