Background: An anterior cruciate ligament (ACL) injury is a severe injury that may require ACL reconstruction (ACLR) to enable the return to sport. Risk factors for ACLR have not firmly been established in the general adolescent population.
Purpose: To investigate the incidence and risk factors for ACLR in a population-based cohort of adolescents.
Study design: Cohort study; Level of evidence, 3.
Methods: We prospectively followed 7644 adolescents from the adolescent part of the Nord-Trøndelag Health Study, included from 2006 to 2008. The main risk factors of interest were the level of sport participation (level I, II, or III) and sport competitions. The endpoint was primary ACLR recorded in the Norwegian National Knee Ligament Registry between January 2006 and December 2013.
Results: A total of 3808 boys and 3836 girls were included in the analyses. We identified 69 (0.9%) ACLRs with a median of 7.3 years of follow-up, providing an overall ACLR incidence of 38.9 (95% CI, 30.7-49.3) per 100,000 person-years. The hazard ratio (HR) for ACLR associated with level I sport participation was 3.93 (95% CI, 0.92-16.80) for boys and 3.31 (95% CI, 1.30-8.43) for girls. There was a stronger association related to participating in sport competitions. Girls had over 5 times a higher risk (HR, 5.42; 95% CI, 2.51-11.70) and boys over 4 times the risk (HR, 4.22; 95% CI, 1.58-11.30) of ACLR compared with those who did not compete.
Conclusion: Participating in level I sports and sport competitions significantly increased the risk of undergoing primary ACLR. Preventive strategies should be implemented to reduce the incidence and future burden of ACLR.
Keywords: ACL; adolescents; epidemiology; injury prevention; risk factors; sport participation.
© 2016 The Author(s).