Figure 1

This schematic diagram illustrates the key radiographic landmarks used to define the axial alignment parameters. H, femoral head center; K, knee joint center; A, ankle joint center; Fs, midpoint of cortical width at lesser trochanter; Fd, a point bisecting the shaft 10 cm proximal to the knee joint. A point bisecting the shaft midway between Fs and Fd was designated as Fc; H-K-A, mechanical axis of the lower extremity; HK-FcK, the valgus correction angle of the distal femur (measured using the method described by Yau et al. [18]); FsFc-FcFd, the coronal femoral bowing angle.