Mechanisms underpinning the peak knee flexion moment increase over 2-years following arthroscopic partial meniscectomy

Background: Knee osteoarthritis is common in people who have undergone partial meniscectomy, and a higher external knee flexion moment during gaitmay be a potential contributor. Although the peak external knee flexionmoment has been shown to increase from3 months to 2 years following partial meniscectomy,mechanisms underpinning the increase in the peak knee flexion moment are unknown. Methods: Sixty-six participants with partial meniscectomy completed three-dimensional gait (normal and fast pace) and quadriceps strength assessment at baseline (3 months following partial meniscectomy) and again 2 years later. Variables included external knee flexion moment, vertical ground reaction force, knee flexion kinematics, and quadriceps peak torque. Findings: For normal pace walking, the main significant predictors of change in peak knee flexion moment were an increase in peak vertical ground reaction force (R2 = 0.55), mostly due to an increase in walking speed, and increase in peak knee flexion angle (R2=0.19). For fast pace walking, the main significant predictors of change in peak knee flexionmomentwere an in increase in peak vertical ground reaction force (R2=0.51) and increase in knee flexion angle at initial contact (R2=0.17). Change in peak vertical forcewasmostly due to an increase in walking speed. Interpretation: Findings suggest that increases in vertical ground reaction force and peak knee flexion angle during stance are predominant contributors to the 2-year change in peak knee flexion moment. Future studies are necessary to refine our understanding of joint loading and its determinants following meniscectomy.