Association of Quadriceps Strength Symmetry and Surgical Status With Clinical Osteoarthritis Five Years After Anterior Cruciate Ligament Rupture

Objective The objective of this study was to examine the association of quadriceps strength symmetry and surgical status (anterior cruciate ligament [ACL] reconstruction or nonoperative management) with early clinical knee osteoarthritis (OA) 5 years after ACL injury or reconstruction. Methods In total, 204 of 300 athletes were analyzed 5 years after ACL injury or reconstruction. Quadriceps strength was measured and reported as a limb symmetry index. We identified participants with early clinical knee OA using the criteria that 2 of 4 Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales score ≤85%. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression and adjusted for age, sex, meniscal injury, and body mass index to examine the associations of quadriceps strength and surgical status with clinical knee OA. Results In all, 21% of participants met the KOOS criteria for clinical knee OA. For every 1% increase in quadriceps limb symmetry index, there was a 4% lower odds of clinical OA (adjusted OR [ORadj] 0.96 [95% CI 0.93–0.99]) at 5 years. Surgical status was not associated with clinical knee OA (ORadj 0.58 [95% CI 0.23–1.50]). Conclusion More symmetric quadriceps strength, but not surgical status, 5 years after ACL injury or reconstruction was associated with lower odds of clinical knee OA.