INFLUENCE OF POSTERIOR TIBIAL SLOPE ON THE FLEXION GAP IN TOTAL KNEE ARTHROPLASTY

BackgroundAdjusting the joint gap length to be equal in both extension and flexion is an important issue in total knee arthroplasty (TKA). Tight flexion gaps occur sometimes, particularly with the cruciate-retaining (CR) type of TKA, and it impede knee flexion. In posterior stabilizing (PS) TKA, because sacrificing the PCL increases the flexion gap, the issue of gap balancing with PS-TKA is usually focused on decreasing the enlarged flexion gap to be equal to the extension gap. It is generally known that posterior tibial slope would affect the flexion gap, however, the extent to which changes in the tibial slope angle directly affect the flexion gap remains unclear. This study aimed to clarify the influence of tibial slope changes on the flexion gap in CR- or PS-TKA.MethodsThe flexion gap was measured using a tensor device with the femoral trail component in 20 cases each of CR- and PS-TKA. A wedge plate with a 5° inclination was placed on the tibial cut surface by switching its front–back direction to in...