ACL Injuries in Major League Soccer: A 10-Year Analysis of Injury Rate and Return to Play, and Performance Metrics by Player Position

Abstract

Background: Anterior cruciate ligament (ACL) injuries are among the most debilitating injuries in professional soccer, often leading to extended recovery times and performance impacts. While much is known about ACL injury outcomes in European leagues, data specific to the Major League Soccer (MLS) remains limited. Purpose/hypothesis: This study aimed to assess the return to play (RTP) times, RTP rates, and performance outcomes after ACL reconstruction in MLS athletes. It was hypothesized that RTP times would improve over the study period and that player performance would stabilize by the third post-injury season, consistent with findings from other professional soccer leagues. Study design: Cohort study; Level of evidence, 3. Methods: The MLS Injury Surveillance database was queried for ACL injuries from 2010 to 2021. Player characteristics, injury characteristics, and performance metrics were collected for 132 players with ACL injuries and compared with 396 uninjured controls matched by age, position, and seasons played. The injured cohort was divided into 2 groups: 2010-2015 and 2016-2021 to compare changes in RTP times, performance outcomes, and trends over time. RTP was defined as participation in at least 1 MLS match after injury. Statistical analyses, including the chi-square and t tests, were performed to evaluate differences between the 2 time periods and matched controls, with significance set at P < .05. Results: RTP time decreased significantly from 269.6 days (2009-2015) to 219 days (2016-2021) (P = .044). Forwards experienced significant performance declines starting in the third post-injury year, with reductions in goals scored, minutes played, and offsides (P < .05). Midfielders showed improved performance in goals scored by the third post-injury year, while defenders exhibited recovery by the second year, with no significant long-term performance deficits. Conclusion: Our study demonstrated that while overall RTP times have improved, position-specific performance outcomes vary significantly, with forwards exhibiting long-term deficits compared with midfielders and defenders. These findings suggest that position-specific rehabilitation protocols may be beneficial for athlete education in RTP and for potential prevention strategies.