胫骨托盘的不同结构设计对胫骨应力分布的影响

The effect of different structural designed tibial tray on the stress distribution of tibia

目的通过设计不同结构类型的人工膝关节胫骨衬垫托盘模型,建立模拟人体单腿站立状态下的有限元模型并进行仿真分析,对比胫骨衬垫托盘的实体结构设计假体与骨小梁结构设计假体在植入胫骨后的应力传导效果以及应力分布差异,从而探究结构设计对金属植入物性能的影响。方法首先采用3-matic11.0处理软件对人工膝关节胫骨衬垫实体托盘进行骨小梁结构设计优化,并将两种结构设计的胫骨托盘假体与胫骨模型在Hypermesh14.0软件中进行有限元前处理,最后利用有限元软件Abaqus6.13中进行手术植入模拟仿真分析并输出胫骨托盘与胫骨上的最大应力与应力分布情况。结果当植入胫骨托盘为实体结构设计时,最大应力值为13.72 MPa;然而,当植入胫骨托盘为骨小梁结构设计时,胫骨应力分布范围在胫骨近端分布范围增大,并且最大应力值(18.38 MPa)也增加了约34%。结论骨小梁结构设计的人工膝关节胫骨衬垫托盘可以有效降低应力遮挡水平,从而避免由于应力遮挡现象所造成的假体早期松动现象,提高了假体的使用寿命。

Objective To study and compare the physical structure of the tibial pad tray design prosthesis and the difference between the stress transmission effect and the stress distribution of the trabecular.And further exploring the influence of the structure design on the performance of the metal implant by designing prosthesis after implantation in the patient’s tibia,and establishing a finite element model that simulates a human standing on one leg.Methods Firstly,3-matic11.0 processing software was used to optimize the trabecular structure of the artificial knee joint tibial pad solid tray.The tibial tray prosthesis and tibial model of the two structural designs were subjected to finite element analysis in Hypermesh 14.0 software.Pre-processing,and finally use the finite element software Abaqus 6.13 to carry out surgical implant simulation analysis and output the maximum stress and stress distribution on the tibia tray and tibia.Results The maximum stress was 13.72 MPa when the tibial tray was designed as a solid structure.However,when the implanted tibial tray was designed for trabecular bone structure,the tibial stress distribution range increased in the proximal tibial component and the maximum stress value(18.38 mpa)increased by about 34%.Conclusion The tibial pad tray designed with bone trabecular structure can effectively reduce the stress shielding level of the artificial knee joint,thus avoiding the early loosening of the prosthesis caused by the stress shielding phenomenon and improving the service life of the prosthesis.