Reported Anterior Cruciate Ligament Injury Incidence in Adolescent Athletes is Greatest in Female Soccer Players and Athletes Participating in Club Sports: A Systematic Review and Meta-Analyses

Purpose To identify the risk of anterior cruciate ligament (ACL) injury in adolescent athletes based on sex, sport, and sport affiliation. Methods A literature search was performed using three online databases (PubMed, Cochrane Library, and EMBASE) from database inception to November 2023 per the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Included studies consisted of level I or II studies reporting on ACL injury exposures in time (hours) or injuries per 1000 athlete-exposures (AE) (1 game or practice) in adolescent athletes. Exclusion criteria consisted of non-English studies, case reports, animal/cadaveric studies, and review articles. Methodological quality and bias assessment of the included studies was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. ACL injuries were analyzed and pooled to calculate incidence rates (IRs), per-season risk, and relative risk (RR) based on sex, sport, and sport affiliation (club sport participation vs school sport participation). Results A total of 1,389 ACL injuries over 19,134,167 AE’s were identified (IR, 0.075 [95% CI, 0.071-0.079]). Of these, 670 ACL injuries were reported in female athletes over 7,549,892 AEs (IR, 0.089 [95% CI, 0.087-0.091]) with 719 in males over 11,584,275 AEs (IR, 0.062 [95% CI, 0.058-0.067]). The greatest RR for ACL injury in females was in soccer (RR, 3.12 [95% CI, 2.58-3.77]) for AEs. The greatest per-season risk of ACL injuries reported in female athletes occurred in soccer (1.08%), basketball (1.03%), and gymnastics (1.01%). The greatest per-season risk of ACL injuries reported in male athletes occurred in football (0.82%), lacrosse (0.64%), and soccer (0.35%). Club sport participation, in both AE (RR, 3.94 [95% CI, 3.19-4.87]) and hours of exposure (RR, 1.57 [95% CI, 1.07-2.28]), demonstrated an increased risk of ACL injury. Conclusion The risk of ACL injuries was 1.56-fold greater in adolescent female athletes compared to male athletes. The highest-risk sport for females was soccer. Participation in club sports possessed higher rates of injury compared to school sports.