Ankle Arthritis: Supra-malleolar Osteotomy

Osteoarthritis of the ankle (OA) is typically developed post-traumatically and affects physically active middle-aged people. The supramalleolar osteotomy of the tibia (SMOT) technique appears as an alternative to ankle arthroplasty or arthrodesis as a joint-preserving technique for asymmetric OA of the ankle. Progressive pain in the articular joint line, as well as a deep aching within the joint range of motion, either localized in the medial or lateral gutter or around the whole hindfoot, are the main symptoms of ankle arthritis. The degree of arthritic changes in the ankle joint is usually described using the Takakura classification, using a weight-bearing anteroposterior radiograph of the ankle. The aim of this technique is to transfer the mechanical axis from a degenerated articular area to a less affected one with preserved articular cartilage. Varus deformities with more than 10° should be corrected with a lateral closing wedge osteotomy, explaining that with a medial opening wedge osteotomy, the fibula would prevent correction. On the other hand, medial opening wedge osteotomy does not affect the limb length and uses a simple approach. However, it needs bone graft and is less stable with higher rates of nonunion. A medial closing wedge osteotomy or a lateral opening wedge osteotomy can be performed to correct a valgus deformity. Dome osteotomies can also be used to correct either varus or valgus deformities.