Young age and return to play increase the likelihood of subsequent ACL reconstruction in football players: Data from the Swedish National Knee Ligament Registry.

Purpose: To compare football players who have undergone one anterior cruciate ligament (ACL) reconstruction (ACLR) with those who have undergone a subsequent ACLR (revision or contralateral) regarding (1) demographics, (2) football-related factors and (3) injury-specific data.

Methods: Players who voluntarily completed a football-specific questionnaire available at the Swedish National Knee Ligament Registry website between April 2017 and September 2020 at the time of their primary ACL injury were included in the study. The questionnaire covered demographics, football-related activities and injury-specific factors. Subsequent ACLR registrations within 4 years of the primary ACLR were identified in December 2023. Data on game participation post-primary ACLR were retrieved from the Swedish Football Association's administrative system in September 2022.

Results: A total of 992 football players (66% men) were included, of whom 99 (10%) were registered for subsequent ACLRs. Univariable analysis showed that the following factors significantly increased the odds of a subsequent ACLR: female sex, younger age, a lower weight and body mass index, fewer years played, use of knee control exercises during warm-up, more likely to plan a return to football, more game participation registered following the primary ACLR, and shorter time between injury and ACLR. Multivariable logistic regression analysis indicated that the odds of undergoing subsequent ACLR decreased significantly with each additional year of age (odds ratio [OR], 0.87; 95% confidence interval [CI], 0.83‒0.92, p < 0.01). Players using knee control exercises during warm-up (OR, 1.71; 95% CI, 1.08‒2.72, p = 0.02), planning to return to football (OR, 2.74; 95% CI, 1.27‒5.91, p = 0.01), and participating in games after primary ACLR (OR, 1.81; 95% CI, 1.13‒2.91, p = 0.01) increased the odds of undergoing a subsequent ACLR.

Conclusions: Younger age and returning to play after an ACLR significantly increase the likelihood of undergoing a subsequent ACLR in football players.

Level Of Evidence: Level IV.