Progression of Knee Osteoarthritis in Patients Undergoing Medial Opening Wedge High Tibial Osteotomy: A Systematic...

Objectives: Osteoarthritis (OA) of the medial compartment in varus knee is a common degenerative condition. High tibial osteotomy (HTO) has been recognized as a primary joint-sparing procedure. The aim of this systematic review was to investigate functional and radiological outcomes, complications, and the progression of knee OA in patients undergoing medial opening wedge HTO. Methods: A total of 18 studies were included. Patients' demographics, Knee Injury and Osteoarthritis Outcome Score (KOOS), number and types of complications, conversion in arthroplasty surgery rate, survival rate, and radiological evaluation were recorded. Results: A total of 2683 patients were evaluated. The frequency-weighted mean follow-up was 168.6 ± 54.6 months. The mean preoperative KOOS score was 46.5 ± 19, while postoperatively the mean score was 66.4 ± 22.9 (p < 0.001). The pre- and postoperative mTFA angle was -5.7° ± 2.8°, and 1.4° ± 2.4°, respectively; with a statistically significant improvement (p = 0.002). A total of 12.5% of patients had a conversion to a total knee arthroplasty and 1.5% had a conversion to unicompartmental knee arthroplasty, while 1.3% of the patients had a revision surgery unrelated to arthroplasty. The survival rate after 10 years was 86.3%. The nonunion rate was 1.3% and the infection rate was 0.9%. Conclusions: Patients who underwent medial opening wedge HTO achieved a significant correction of mTFA associated with an improvement in functional outcomes. An 86% survivorship rate at 10 years was observed, while a 14% conversion rate to knee arthroplasty for OA progression was reported after a mean follow-up of 14 years.