Osteotomy is an alternative treatment for unicompartmental osteoarthritis of the knee. In genu varum, a high valgus closing wedge osteotomy is preferred, with overcorrection by 5degrees. Complications and poor outcomes can be overcome by incomplete osteotomy with careful preoperative planning, precise use of cutting jigs, compression fixation, and early mobilization and weight bearing. Patella baja is related to postoperative immobilization, and unicompartmental arthroplasties are more difficult to revise because of bone loss. Supracondylar femoral osteotomy is preferred for genu valgum using a lateral opening wedge with a toothed plate, allowing easy access to the lateral compartment of the knee. Osteotomy, far from being obsolete, has art increasing role in joint resurfacing procedures.