Background: In patients undergoing medial open-wedge high tibial osteotomy (MOWHTO), the contralateral knee adduction moment (KAM) increases significantly postoperatively, indicating an increased risk of knee osteoarthritis. However, the factors associated with an increased KAM on the nonoperated side remain unexplored. Purpose: To identify the factors associated with KAM changes on the nonoperated side before and after MOWHTO. Study Design: Cohort study; Level of evidence, 2. Methods: Thirty participants scheduled to undergo MOWHTO were recruited between August 2020 and November 2022. Physical findings and knee alignment were assessed preoperatively and 1 to 2 years postoperatively with 3-dimensional gait analysis. Gait data were collected with a 3-dimensional motion analysis system and 2 force plates. Multiple regression analysis was performed to identify the factors associated with changes in the first and second KAM peaks on the nonoperated side after MOWHTO. Results: The hip adduction moment on the nonoperated side (standard partial regression coefficient SPRC, 0.45; P = .008; 95% CI, 0.37-2.29) and knee adduction angle on the nonoperated side (SPRC, 0.34; P = .041; 95% CI, 1.66-71.41) were significantly associated with the first KAM peak on the nonoperated side ( R 2 = 0.31). Hip adduction moment on the nonoperated side (SPRC, 0.56; P = .001; 95% CI, 0.58-1.97) and frontal pelvic obliquity angle (SPRC, 0.32; P = .040; 95% CI, 0.30-12.25) were significant factors associated with the second KAM peak on the nonoperated side ( R 2 = 0.48). Conclusion: Changes in the first and second KAM peaks on the nonoperated side were significantly associated with surrounding alignment and joint moments during gait. In post-MOWHTO gait, controlling the knee adduction angle during the initial stance phase and contralateral pelvic drop during the terminal stance phase may be associated with a reduced risk of KOA development on the nonoperated side.
Ikematsu et al. (2026) studied this question.