Radiographic measurements of TKA component placement in the sagittal plane. In the sagittal plane, the femoral component is assessed by femoral component flexion angle (FCF), defined as the angle between the distal femoral axis in the sagittal plane and a line perpendicular to the distal surface of the femoral component. A femoral component flexion angle of 0–8° is usually aimed. Tibial component placement is assessed by tibial component slope (TCS), defined as the angle between the line that is perpendicular to the bottom of the tibial plate and the tibial shaft axis in the sagittal plane. TCS measurements must consider that some TKA types have the posterior slope built into the implant design.