EVALUATION OF PCL ELASTICITY IN CRUCIATE-RETAINING TOTAL KNEE ARTHROPLASTY

BackgroundTo prevent excessive tension on the posterior cruciate ligament (PCL) in cruciate-retaining total knee arthroplasty (CR-TKA), some knee prosthesis-systems offer the option of creating a posterior slope for the tibial polyethylene insert. Vanguard® Complete Knee System offers two different types of tibial bearing for CR-TKA. CR Lipped Bearing (LB) has a slightly raised posterior lip, whereas CR Standard Bearing (SB) is recessed downward at the posterior margin and has 3° posterior slope. The objective of this study was to investigate the effect of the tibial bearing slope on PCL load using the original devise in vivo conditions.Material and MethodsTwenty osteoarthritic varus knees were included in this study. After implantation of the trial components, PCL stiffness was measured using the original tension analyzer intra-operatively. Elastic modulus of PCL was calculated at 90 and 120 degrees knee flexion on two types of bearing surface.ResultsElastic modulus of PCL was 7.2±0.9 N/mm (mean±SE) at 9...