Higher Revision and Secondary Surgery Rates in Adolescent ACL Reconstructions Compared to Athletes Over 16 Years Old: A case control study

Background: The incidence of anterior cruciate ligament (ACL) reconstructions among adolescents, particularly those involved in high-risk sports, has increased. Despite surgical advancements, outcomes remain worse than in adults. This study aimed to assess ACL reconstruction outcomes in patients under 16 years and compared to older patients. The prevalence of high pivoting sports in those undergoing revision or contralateral ACL reconstruction was also analyzed. We hypothesized that younger athletes experience poorer outcomes and higher rates of secondary surgeries. Methods: This study evaluated ACL reconstruction outcomes in patients under 16 years (Group 1) and compared them with those over 16 years (Group 2). A retrospective analysis was conducted on patients who underwent primary arthroscopic ACL reconstruction between 2007 and 2022. Ipsilateral and contralateral surgeries were analyzed in both groups. Patient-reported outcomes (Lysholm score, Knee Injury and Osteoarthritis Outcome Score [KOOS], Tegner Activity Scale, and International Knee Documentation Committee [IKDC] scores) were compared between the two groups. The impact of sports activity level and sex on revision rates was examined. Statistical tests, including two-sample Z tests and two-sample t-tests, were used for analysis. Secondary surgeries were defined as additional procedures after ACL reconstruction, microfracture, hardware removal, and arthrolysis. Results: Group 1 (average age: 15.2 years) included 70 patients with a follow-up of 6.9 years, and Group 2 (average age: 30.8 years) included 87 patients with a follow-up of 3.66 years. A significant age difference was found (p<0.001). Group 1 had higher rates of contralateral ACL surgeries (18.3% vs. 1.1%, p=0.03), meniscus surgeries (26% vs. 4.6%, p=0.003), and secondary surgeries (44% vs. 21%, p=0.01) compared to Group 2. Female athletes under 16 years had a significantly higher rate of contralateral ACL reconstruction (92% vs. 69%, p=0.020). In Group 1, the KOOS Pain score was significantly higher (95.6 vs. 94.0, p=0.033), but the Symptoms score was significantly lower (75.6 vs. 85.0, p<0.005). Conclusion: Patients under 16 years undergoing ACL reconstruction had higher rates of both contralateral and ipsilateral ACL surgeries, as well as secondary surgeries, compared to older patients. Female adolescents had a significantly higher incidence of contralateral ACL reconstruction.