Association Between Autograft Choice and Risk of Contralateral ACL Injury in Patients ≤25 Years of Age: A Systematic Review and Meta-analysis

Background: Understanding the risk of secondary contralateral (CL) anterior cruciate ligament (ACL) injury in young patients after ACL reconstruction (ACLR) may help identify targetable risk factors to optimize rehabilitation and return to sport. It is not clear if the autograft type used in the index procedure affects the risk of having a CL injury. Additionally, the aggregated CL injury rates across studies in young patients have not been well described. Purpose: To compare CL ACL injury rates by graft type in patients ≤25 years of age at a minimum follow-up of 24 months after ACLR, and to stratify CL injury rates by potential modifiers, including sex. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review of the literature for studies reporting ACL autograft reinjury rates after ACLR using hamstring tendon (HT), bone–patellar tendon–bone (BPTB), or quadriceps tendon (QT) autograft in patients ≤25 years of age with a minimum follow-up of 24 months was conducted. From this data set, CL ACL injury rates from studies in which they were reported were evaluated. Results: The meta-analysis included 22 studies pooling 4435 total patients who received BPTB (n = 2349), HT (n = 1561), or QT (n = 525) autografts for their ALCR. The pooled CL ACL injury rate was 10.8% (95% CI, 8.2%-14.0%) for HT, 10.5% (95% CI, 7.4%-14.8%) for BPTB, 12.2% (95% CI, 9.7%-15.3%) for QT, and 10.6% (95% CI, 8.8%-12.8%) for all grafts together. There were no differences among primary ACLR graft types in CL ACL injury rates (χ² = 0.7; P = .7). There were differences in CL injury rates by sex among graft types (risk ratio [RR], 0.8; 95% CI, 0.5-1.4; χ² = 9.2; P < .01). Males had a significantly lower risk of CL ACL injury relative to females after primary BPTB ACLR (RR, 0.439), but not HT (RR, 1.050) or QT (RR, 1.219) ACLR. Conclusion: In patients ≤25 years of age, the rates of CL ACL injury are similar after primary HT, BPTB, and QT autograft ACLR. The risk of CL injury was lower in males relative to females after ACLR with BPTB, but not with HT or QT.