膝关节假体股胫接触面积的影响因素

Influencing Factors of Femoro-Tibial Contact Area for Knee Prostheses

目的 通过建立自动化流程对膝关节假体股胫接触面积的影响因素进行分析,总结设计参数对接触面积的影响规律,并找到最大接触应力和接触面积之间的关系。方法 在Isight中建立参数化有限元模型,包括几何模型自动变参、自动化有限元前处理和有限元运算3个组件,实现自动化流程,提取接触面积进行统计学分析。结果有限元模型用Tekscan应力分布系统进行验证。当股骨、胫骨矢状面半径逐渐接近时,接触面积最大为295 mm^2。股骨矢状面半径对接触面积是正效应,而胫骨矢状面半径是负效应。最大接触应力和接触面积近似呈线性负相关。结论 通过分析股胫矢状面半径对接触面积和接触应力的影响规律,为临床降低衬垫磨损提供设计依据。

Objective By developing an automatic procedure for optimization of femoro-tibial contact area for knee prosthesis,to summarize the influence pattern of design parameters on contact area,and discover the relationship between the maximum contact stress and contact area.Methods A parametric finite element(FE)model was developed in the Isight software,which included three components:automatic parameter changes for the geometric model,automatic modeling in the FE software,and automatic FE calculation.The automatic workflow was realized,and then contact areas were statistically analyzed.Results The FE model was validated by using Tekscan pressure distribution system.When the femoral sagittal radius was gradually close to the tibial sagittal radius,the contact area gradually reached to the maximum 295 mm^2.The femoral sagittal radius had a positive effect on contact area,while the tibial sagittal radius had a negative effect.The maximum contact stress had a linear relationship with contact area approximately.Conclusions This study analyzed the influence of femoro-tibial sagittal radius on contact stress and contact area,and the research findings would provide references for the design on reducing wear of tibial insert in clinic.