Osteotomies in Total Knee Arthroplasty

Abstract

Bone cuts and soft-tissue releases are the principal steps in TKA. However, some knees undergoing TKA may require an additional procedure in the form of an osteotomy. An osteotomy in primary TKA is usually indicated in rigid or severe deformities to facilitate soft-tissue balance and deformity correction, to concomitantly correct an extra-articular deformity or rarely to facilitate exposure of the joint. Frequently, in varus arthritic knees undergoing TKA, the medial and posteromedial side of the tibial plateau shows adaptive changes resulting in the formation of a prominent bony flare in this area. This causes local tenting of the medial soft-tissue structures and contributes to knee deformity and medio-lateral soft-tissue imbalance. A reduction osteotomy involves excision of this medial bony flare to decompress the medial soft-tissue structures. Rarely, despite extensive soft-tissue release and a reduction osteotomy, a knee deformity may be too rigid and/or the medio-lateral soft-tissue imbalance too severe to correct. In such cases a sliding medial condylar osteotomy (SMCO) in a varus knee or a lateral epicondylar osteotomy (LEO) in a valgus knee may be required to achieve optimum limb alignment and soft-tissue balance.