Similar quadriceps strength recovery after anterior cruciate ligament reconstruction with rectus femoris, quadriceps tendon and hamstring autografts

PURPOSE: Persistent quadriceps weakness remains a major concern following anterior cruciate ligament reconstruction (ACLR), and graft harvest site may influence postoperative strength recovery. The purpose of this study was to compare quadriceps strength recovery at 12 months following ACLR using rectus femoris (RF), quadriceps tendon (QT), or hamstring (HS) autografts. We hypothesised that RF reconstruction would demonstrate quadriceps recovery that is non-inferior to QT and HS autografts. METHODS: A prospective comparative cohort study was conducted, including 90 patients undergoing primary ACLR (30 RF, 30 QT and 30 HS). Isokinetic assessment was performed at 12 months. The primary outcome was quadriceps peak torque limb symmetry index (LSI) at 60°/s. A non-inferiority margin of 10% points was predefined. Outcomes were analysed using analysis of covariance adjusted for age, body mass index and sex. Estimated marginal means (EMMs) and 95% confidence intervals (CIs) were calculated. RESULTS: Adjusted EMMs for quadriceps peak torque LSI at 60°/s were 81.4% (95% CI 73.2-89.6) for RF, 73.4% (95% CI 65.2-81.6) for QT and 71.5% (95% CI 63.2-79.7) for HS. No differences between groups were detected (p = 0.204). Pairwise adjusted differences were 7.9% for RF versus QT (95% CI -6.3 to 22.2; p = 0.529) and 9.9% for RF versus HS (95% CI -4.3 to 24.1; p = 0.280). Under the predefined non-inferiority margin, RF was non-inferior to both QT and HS autografts. No significant differences were observed for secondary isokinetic parameters or hamstring-to-quadriceps ratios. CONCLUSION: At 12 months following ACL reconstruction, quadriceps strength recovery after RF autograft was similar to that observed after QT or HS grafts. When evaluated within a clinically relevant non-inferiority framework and adjusted for biological covariates, ACLR with RF autograft does not appear to yield worse extensor performance at mid-term follow-up relative to other common graft types. LEVEL OF EVIDENCE: Level II.