Effect of lengthening along the anatomical axis of the femur and its clinical impact

Figure 1 Femoral lengthening along the anatomical axis (length) affects the femoral anatomical mechanical angle (assumed to be 7 degrees). Increasing the femoral length along the anatomical axis would cause degrease in the anatomical mechanical angle (θ).

Figure 2 Calculation of the changes in the θ angle after lengthening of different sizes of femora using Law of Sines (A-F).