The deformities of the lower limbs (genu valgus and genu varus) are alterations frequently developed properly by physiological processes which usually disappear at 2 years (genu varus) and at 7-8 years (genu valgus), being considered in adults normal a 4º-6º genu valgus, however the appearance of the latter is also related to various metabolic pathologies, tumors, traumatic sequelae, infections, skeletal dysplastic and idiopathic genu valgus. In the bibliography, there is a greater consensus on the approach to varus deformity, not so in valgus deformities, where there is no bibliography with a level of evidence that defines established protocols to treat severe valgus deformities>20, currently good treatment results have been demonstrated by means of knee arthroplasty to correct genu valgus deformities, which showed good results in the alignment of the lower extremities through the balance of ligaments in patients with severe genu valgus with pain reduction. , improvements in knee function and with a low rate of complications, the use of these alternatives such as the external approach in total knee replacement in patients with severe genu valgus and medial collateral ligament insufficiency allows correcting large deformities using a technique simple and in most cases without the use of a prosthesis that generates a degree of constraint, progressively improving their living conditions.