Is 9 months the sweet spot for male athletes to return to sport after anterior cruciate ligament reconstruction?

Objective Most studies examining the time to return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) do not account for the athlete's physical readiness. This study aimed to investigate the status of male athletes at 2 years after ACLR, the factors affecting a return to pivoting sports, and the association between time to RTS and subsequent knee injury risk for those athletes who met discharge criteria. Methods We prospectively followed 530 male athletes (mean age 26.7 +/- 7.7 years) participating in pivoting sports throughout rehabilitation and at 2 years after ACLR. Pair-wise analyses were conducted to compare athletes who returned to pivoting sports and those who did not. We performed a Cox regression analysis to assess the association between subsequent non-contact or indirect contact knee injuries and time to RTS. Pearson's chi 2 test was used to compare athletes who RTS in <= 9 months to those who RTS in >9 months after ACLR. Results In total, 379 (72%) athletes returned to pivoting sports at 2 years after ACLR. Athletes who completed rehabilitation and met discharge criteria (n=190) were almost 6 times more likely to return to their preinjury sport (OR 5.71; 95% CI 3.39 to 9.62). Of those who did not complete their rehabilitation (n=340), 132 (39%) did not return to pivoting sports. For athletes who met discharge criteria, time to RTS was not associated with the risk of new knee or ACL injury. There was no increased risk for new knee (HR 0.892, 95% CI 0.39 to 2.07, p=0.79) or ACL (HR 0.718, 95% CI 0.24 to 2.17, p=0.56) injury whether athletes returned before or after the 9-month mark following ACLR. Conclusions Completing rehabilitation and meeting objective criteria significantly increased the odds for male athletes to return to pivoting sports. Time to RTS did not impact the risk for a new knee or ACL injury if athletes met objective criteria.