Figure 1. Varus-valgus angle and related medial collateral ligament injury (a). The force transferred from the femur to the tibia can be decomposed as shown in (b) in normal and tangential forces. In (c) F1 and F2 are forces normal to tibial plateau, t1 and t2 tangential forces. A decrease of 10° of varus-valgus angle respect to normal physiology increases tibial plateau tangential force of a factor of 2.