Total knee arthroplasty coincident with high tibial osteotomy

Abstract

Established lower limb alignment and knee stability are the two main prognosis factors influencing good functional result and prosthesis life. During Total Knee Arthroplasty (TKA), correction of tibial extra-articular deformity cannot be achieved without ligament balancing. Excessive valgus deformity after a failed high tibial osteotomy (HTO) necessitates a much larger resection of bone from the medial tibial plateau resulting in a trapezoidal extension gap. In overcorrected valgus knee patients after failed HTO, meticulous preoperative planning is required to predict complementary procedures needed to achieve flexion-extension balance with optimal postoperative lower limb alignment. This article details the preoperative planning involved and the intraoperative technique used in such cases. We describe a planning methodology consisting of measuring medial and lateral distance between future femoral and tibial orthogonal resection lines, drawn on valgus and varus stress radiographs (arrows). If the medial distance (medial arrows) on the valgus stress radiographs is longer than the lateral arrows on the varus stress radiographs, a lateral release will be necessary to achieve a rectangular extension gap during TKA procedure. However, the lateral release needed to compensate medial bone resection is limited. This limit must not exceed 10 millimeters (about 8 to 10° of valgus malunion). Over this limit, total knee arthroplasty plus corrective tibial osteotomy is one of the solutions. We prefer to insert prosthesis inside the “ligament box”; without any ligamentous release. The limb alignment is achieved with corrective tibial osteotomy. We propose and describe how to carry out TKA based on a rectangular extension gap, associated, in the same procedure, with a HTO to restore a neutral alignment of the leg.