A finite element analysis for predicting outcomes of cemented total knee arthroplasty

The study was designed to assess the validity of a finite element analysis for predicting the behavior of cemented knee implant used in total knee arthroplasty (TKA), for different mechanical loads, and correlation with clinical outcomes of this procedure. We conducted computational simulations using finite element analysis of two situations: i) The ideal prosthetic component positioning; and ii) variable varus tibial malposition, but with a balanced knee. A total of 80 cemented TKAs performed on 70 patients were divided into two groups. Patients from one group required secondary asymmetric tibial recut for balancing the prosthetic knee and patients from the other group, did not. In regards to the results, we observed no differences upon analysis of the postoperative results of the Knee Society Score (KSS), the angle between the femur and tibia, the range of motion and frontal laxity between groups. The finite element analysis showed that in a 3˚ varus inclination of the joint interline, but with a balanced knee, the maximum contact stress, measured on the tibial plateau surface, increased by 11% compared to the value of mechanical alignment. In conclusion, analysis of the computational model using finite elements showed predictable results of cemented TKA for the different situations of mechanical loads.