Fig. 2

Plain antero-posterior radiograph of a right knee with a Schatzker II, AO/OTA 41-B3.1 fracture. Line A represents the tibial plateau width (the width of the tibial plateau at its widest point). Line B represents the femoral condyles width (the width of the femoral condyles at their widest point). To compensate for any magnification error, a unitless ratio was calculated in order to depict tibial widening: Tibial Widening Ratio (TWR) = Line A/Line B. In the case illustrated, TWR was 8.85/8.57 = 1.03