The aim of supramalleolar conversion osteotomy is to reduce the pain of the patient and stop or at least slow down joint degeneration. The indication for supramalleolar osteotomy is asymmetric osteoarthritis of the ankle joint with varus or valgus deformity. Good clinical results for arthritis can be achieved in the early or middle stages. Besides closing and opening wedge osteotomies dome osteotomy is sometimes indicated, especially for larger deformities. The preoperative preparation of individual patient-specific section blocks facilitates the intraoperative implementation and seems to increase the precision. Further studies are necessary to support this. The indications for additional procedures, such as fibular osteotomy are still being discussed. Inframalleolar osteotomy and soft tissue interventions are frequently necessary for balancing the foot.