Career Length and Injury Incidence After Anterior Cruciate Ligament Reconstruction in Major League Soccer Players

Background Little is known about career length after anterior cruciate ligament (ACL) reconstruction in Major League Soccer (MLS), the top men's professional soccer league in the United States. Further, it is unspecified whether athletes returning to soccer after ACL reconstruction are at a higher risk for injuries, beyond new knee injuries. Purpose To examine career length and the incidence of lower extremity injuries in MLS athletes after ACL reconstruction in comparison with age-matched controls. Study Design Cohort study; Level of evidence, 3. Methods Injuries and athletic exposures (AEs; games and training sessions) were recorded in the HealtheAthlete database, the injury surveillance system of MLS. All athletes who had undergone ACL reconstruction and returned to MLS were identified and age-matched with controls. Multivariate analyses of variance were used to compare career length and percentage of regular/postseason games that athletes started, substituted, or did not play. Generalized linear model regressions were used to examine the injury risk. Results Athletes in the ACL group had shorter careers (1.3 ± 1.3 years) than those in the control group (2.5 ± 1.3 years) (P < .01), but while they were playing, athletes in the ACL group participated in a similar number of AEs as those in the control group (169.9 ± 129.0 vs 171.6 ± 124.9 AEs, respectively; P = .95). Athletes in the ACL group started fewer regular/postseason games (36.7% ± 34.3% vs 60.1% ± 33.8%, respectively; P < .01) and did not play in more regular/postseason games (47.4% ± 35.5% vs 31.0% ± 34.4%, respectively; P = .03) compared with those in the control group. The ACL group was not at a significantly greater risk for lower extremity injuries compared with the control group (relative risk, 0.87; 95% CI, 0.55-1.37). Conclusion Although MLS athletes after ACL reconstruction are not at a greater risk for lower extremity injuries, this study suggests that they are not utilized in regular/postseason games as frequently and that their careers in MLS are shorter than age-matched controls. Further research is necessary to elucidate reasons for these athletes' shortened MLS careers. This study supports the view of return to sport not as a single time point but as a continuum from return to participation to return to play and return to performance.