Fixed bearing knee congruency -- influence on contact mechanics, abrasive wear and kinematics

The objective of our study was to evaluate the in vitro wear behavior of fixed bearing designs for total knee arthroplasty in relation to contact mechanics and resultant kinematics for different degrees of congruency. a finite element model was created for three knee articulations with increasing degrees of tibio-femoral congruency (flat, curved, and dished design). For the three different knee design configurations, in vitro wear simulation was performed according to iso 14243-1. Contact areas increased with increasing knee congruency, whereas the peak surface contact stresses decreased. The wear rates for the knee design configurations differed substantially between the three test groups (flat, curved, and dished). our observations demonstrate that increased congruency in conjunction with decreased surface contact stresses significantly contributes to reducing wear in fixed bearing knee articulations.