Conversion of high tibial osteotomy to unicompartmental knee arthroplasty: Surgical pearls to ensure a successful outcome

Historically, high tibial osteotomy (HTO) was considered a contraindication for medial unicompartmental knee arthroplasty (UKA). While some recent reports demonstrate good outcomes after UKA for failed HTO, revision to UKA after failed HTO remains controversial. UKA after HTO is a demanding procedure primarily related to preoperative valgus alignment, residual medial knee laxity and abnormal proximal tibia geometry. The aim of this technical note is to present surgical pearls and strategies to ensure a successful outcome of UKA after a failed HTO.