Fourfold higher graft failure risk with isolated BPTB versus hamstring ACL reconstruction with ALL in patients under 25 years: A prespecified subgroup analysis of a randomized controlled trial.

PURPOSE: To compare 5-year graft failure rates between isolated bone-patellar tendon-bone anterior cruciate ligament reconstruction (BPTB-ACLR) and hamstring tendon (HT)-ACLR combined with anterolateral ligament reconstruction (ALLR) in patients younger than 25 years. METHODS: A prespecified subgroup analysis was performed on patients younger than 25 years enroled in a prospective comparative study. Patients underwent either isolated ACLR using a BPTB-ACLR or hamstring ACLR combined with ALLR (HT-ACLR + ALLR). The primary outcome was graft failure at 5 years. Secondary outcomes included patient-reported outcome measures (Knee injury and Osteoarthritis Outcome Score [KOOS], International Knee Documentation Committee [IKDC], Lysholm and Tegner scores). Survival analysis was performed using Kaplan-Meier estimates and log-rank testing. Multivariate logistic regression and Cox proportional hazards models were used to identify independent risk factors for graft failure. RESULTS: The analysis included 281 patients younger than 25 years, with 134 undergoing isolated BPTB-ACLR and 147 undergoing HT-ACLR + ALLR. At 5 years, graft failure occurred in 22 patients (16.4%) in the isolated BPTB-ACLR group and in 7 patients (4.8%) in the HT-ACLR + ALLR group (p = 0.0013). Kaplan-Meier analysis demonstrated significantly improved graft survival in the HT-ACLR + ALLR group (log-rank p = 0.0008). On multivariate analysis, isolated BPTB-ACLR was independently associated with a higher risk of graft failure compared with HT-ACLR + ALLR (odds ratio 4.2; 95% confidence interval [CI] 1.8-11.3; p = 0.0007; hazard ratio 4.2; 95% CI 1.9-10.7; p = 0.0002). Clinical outcome scores were comparable between groups at follow-up across all patient-reported measures. CONCLUSION: This secondary analysis of a RCT with 5-year follow-up showed that, in patients younger than 25 years, HT-ACLR combined with ALLR was associated with a significantly lower risk of graft failure compared with isolated BPTB-ACLR, whereas patient-reported clinical outcomes were comparable between groups. LEVEL OF EVIDENCE: Level I, randomized controlled trial.