Fig. 1.

Radiograph showing the measured angles in the coronal plane. Depicting the angle between the femoral and mechanical axis (the hip knee angle [HKA]), the angle between the anatomical femoral and tibial axis (the femoral tibial angle [FTA]), the angle between the tangent to the most distal part of the femoral condyles and the mechanical axis (the frontal femoral component angle [FFC]), and the angle between the tangent to the tibial base plate and the mechanical axis (the frontal tibial component angle [FTC])