Valgus osteotomy of the proximal tibia remains the treatment of choice for the young active patient with a progressively symptomatic varus knee and mild to moderate secondary osteoarthritis. Although the natural history of the varus knee is not well established, it is widely accepted that patients with varus malalignment who develop meniscal injuries or progressive cartilage wear will inevitably develop more severe medial compartment osteoarthritis unless the abnormal mechanics of the knee are corrected.