Intraoperative Complications in Medial Opening Wedge High Tibial Osteotomy.

Medial opening wedge high tibial osteotomy has been established for treatment of medial symptomatic knee arthrosis with varus malalignment in young and elderly but active patients. To obtain satisfactory results, it is essential for surgeons performing osteotomy to identify, prevent, and treat potential intraoperative adverse events. Lateral hinge fracture (LHF) is the most common intraoperative complication while popliteus artery injury is rare but limb-threatening. Computed tomography is the benchmark to detect LHF, the risk of which increased markedly with the opening gap larger than 11 mm. Setting the lateral hinge in a safe zone is the most important preventive measure. Medial long locking plate fixation may allow patients even with unstable hinge fractures to start early full weight bearing. Additional fixation of LHF is optional, and bone void filling is not routinely used. For protection of popliteus artery injury, flexing the knee joint is unreliable. It is paramount to place a protective retractor just behind the posterior tibial cortex toward the proximal tibiofibular joint before osteotomy, particularly in case of aberrant artery. A repertoire of surgical pearls is described in detail in this review to identify, prevent, and manage those intraoperative complications.