Comparison of four-pegged and stemmed tibial plate designs: a three dimensional finite element analysis / 中华骨科杂志

ABSTRACT

Objective To evaluate the biomechanical features of four-pegged and stemmed tibial plate designs under different loads. Methods Three dimensional finite element models of four-pegged and stemmed tibial plate designs implanted on the tibia were constructed. The models were tested under vertical compression loads and rotational loads to compare their biomechanical responses and fixation strength, such as peak contact pressure and contact stress, peak contact sliding distance, displacement of the tibial plate,and peak Mises stress. In order to compare their stress shielding effect on the proximal tibia, four paths in four different locations of the proximal tibial cancellous bone were selected, and the Mises stress in 15 different points of each path were compared. Results The general biomechanical responses of the two designs,as peak contact pressure and contact strain, peak contact sliding distance, displacement of the tibial plate,and peak Mises stress,were similar under vertical loads and rotational loads. The Mises stress of all 15 points in four paths in the cancellous bone below stemmed tibial plate was smaller than that of below fourpegged tibial plate under vertical compression load. Conclusion Four-pegged tibial plate was comparable with stemmed tibial plate in fixation strength. The biomechanical effect of stress shielding in the proximal tibia of the stemmed tibial plate was bigger than that of the four pegged tibial plate.