Return to sport after primary anterior cruciate ligament reconstruction in athletes with a preinjury Tegner Activity Scale ≥7: a longitudinal, nationwide, registry-based cohort study

Objective This study aimed to longitudinally assess the rate and timing of return to sports (RTS) and its predictors after primary anterior cruciate ligament reconstruction (ACL-R) in preinjury Tegner Activity Scale≥7 (TAS≥7) athletes. Methods This prospective, longitudinal, registry-based cohort study included 511 athletes aged 16–40 with a preinjury TAS≥7 registered in the Swedish National Knee Ligament Registry following primary ACL-R. The primary outcomes were RTS TAS≥7 and associated predictors. Secondary outcomes included RTS at preinjury TAS levels, associated predictors, secondary ACL injury rates and assessment of patient-reported outcome measures (PROMs). Associations were analysed using log-binomial and multivariable Cox regression. Results 62% (n=315) achieved RTS TAS≥7 after ACL-R within 12.3 months (SD 4.7), while only 51% achieved RTS preinjury TAS level within 12.7 months (SD 4.9). Negative predictors for RTS TAS≥7 included female sex, older age, low sporting level and delayed surgery. ACL-Return to Sports after Injury (ACL-RSI) score >4.2 at 3 months postoperatively was associated with higher likelihood of RTS TAS≥7 and RTS preinjury TAS level. No differences in secondary ACL injury rates were observed between RTS groups or sexes, with overall secondary ACL injury rates of 9.2% (n=47) within 24 months. Participants returning to TAS≥7 reported better PROMs. Conclusion Three out of five athletes returned to knee-demanding sports following ACL-R. Female sex, older age, lower sporting level and delayed surgery were associated with reduced RTS≥7 rates. Psychological readiness at 3 months post-surgery emerged as a potentially modifiable factor associated with RTS outcomes after ACL-R.