Medial Opening Wedge (MOW) Versus Lateral Closing Wedge (LCW) High Tibial Osteotomies for Knee Medial Compartment Osteoarthritis Show Similar Outcomes and Survivorship, While MOW Has Higher Rates of Tibial Fracture and LCW Has Higher Rates of Nerve Injury and Conversion to Total Knee.

Purpose: The purpose of this systematic review was to compare the clinical and radiographic outcomes and complications between medial opening wedge and lateral closing wedge high tibial osteotomies in the setting of medial compartment osteoarthritis with genu varus alignment.

Methods: This study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies that reported on MOW- or LCWHTOs in the setting of medial compartment osteoarthritis were included. Analysis was performed based on radiographic and patient reported outcomes (PROs) and complications.

Results: A total of 40 studies were included. Hip-knee-ankle (HKA) angles and PROs including Lysholm and VAS showed significant improvements postoperatively for both MOW- and LCWHTO for all included studies. For the studies that reported on it, posterior tibial slope (PTS) was significantly increased in 4 of the 9 MOW studies and significantly decreased in 8 of the 9 LCW studies, and patellar height was significantly decreased in 4 of the 5 MOW studies, while none of the 4 LCW studies reported any changes. Three comparison studies reported a higher conversion to total knee arthroplasty (TKA) in the LCW cohort, otherwise, survivorship at 10-years was comparable between studies. The MOW cohort had higher rates of tibial fractures while the LCW cohort had higher rates of nerve injuries.

Conclusions: This systematic review found comparable HKA angle correction and PROs between patients undergoing MOW- or LCWHTOs to treat medial compartment osteoarthritis. Survivorship at 10-years was comparable between MOW- and LCWHTOs; however, some MOW- and LCWHTO comparison studies reported higher conversion to TKA for LCWHTO. Medial opening wedge HTO typically results in an increased PTS, decreased patellar height, and tibial fractures, while LCWHTO typically results in decreased PTS, no change in patellar height, and common peroneal nerve injuries.

Level of evidence: Level IV, systematic review of Level I to IV studies.