Knee osteoarthritis is a common and disabling disorder made worse by lower extremity malalignment. Medial knee arthrosis is the most common indication for high tibial osteotomy (HTO). Surgical techniques include closing wedge osteotomy, opening wedge osteotomy, dome osteotomy, progressive callus distraction, and chevron osteotomy. Opening and closing wedge osteotomies are the most common. While lateral closing wedge HTO was once considered standard of care, both techniques have advantages and disadvantages, and neither has proven clinical superiority. Technique selection, therefore, is largely driven by surgeon preference.