Impact of playing position on ACL injury characteristics, risk and career outcomes in football-An analysis of 742 cases of the ACL registry in German football.

PURPUSE: To evaluate how playing position affects anterior cruciate ligament (ACL) injury features, incidence rates and career outcomes across competition levels in male football.

METHODS: Using the prospectively collected 'ACL Registry in German Football', we analysed six seasons (2016-2022) across professional (first to third leagues), semi-professional (fourth to sixth) and amateur (seventh) levels. In professional players, return-to-performance over five seasons was evaluated with linear mixed-effects models, and career outcomes within three seasons after injury were assessed. Injury mechanisms were examined across all levels. Outcomes were stratified by position (goalkeeper [GK], defender [DF], midfielder [MF], forward [FW]).

RESULTS: A total of 742 ACL injuries were analysed (professional n = 172, semi-professional n = 316, amateur n = 254). Among professionals, FWs showed the highest rate of a drop in competitive level (47.5%), and GKs a numerically higher rate (54.5%); however, the GK comparison was not statistically significant after correction for multiple testing and should be regarded as exploratory. Mixed-effects models for matches and minutes played showed significant main effects for time and position (all p < 0.001) but no significant interaction (p = 0.064 matches; p = 0.105 min). Match-related incidence was highest in DFs (0.397/1000 player-hours) and MFs (0.370). Injury mechanisms varied by level; direct contact accounted for 66.7% and 46.2% in professional FWs and DFs, respectively, whereas non-contact injuries predominated across all positions in amateur players.

CONCLUSIONS: The characteristics and outcomes of ACL injuries may vary by position. Match-related injury rates tended to be highest for DFs and MFs, while career-altering effects appeared most pronounced in FWs, with an exploratory, non-significant tendency also for GKs. Injury rate and consequence should be considered separately. Although non-contact injuries are most common overall, direct contact injuries were relatively frequent among professional FWs and DFs. Prevention and rehabilitation strategies could be tailored to each position.

LEVEL OF EVIDENCE: Level II, prospective cohort study.