Fig. 1.

(a) Femorotibial angle: the femorotibial angle (FTA) is the lateral angle between the axis of the femoral shaft and that of the tibial shaft. An increased FTA is called varus alignment while a decreased FTA is called valgus alignment. (b) Femur neck-shaft angle: a decreased femur neck-shaft angle is called coxa vara or varus alignment. An increased neck-shaft angle is called coxa valga or valgus alignment. (c) Femoral bowing angle: femoral bowing angle is line that best describes the midpoint of the endosteal canal of the femoral diaphysis was drawn in the proximal and the distal quarters