Anterior Cruciate Ligament Ruptures in NFL Players Are Associated With Position- And Task-Specific Performance Changes

Studies assessing National Football League (NFL) performance following ACL reconstruction show mixed results,1–4 but rely on traditional metrics (yards gained, receptions, touchdowns, fumbles). These metrics are influenced by randomness as they rely on rare events (touchdowns, fumbles) and fail to isolate individual performance due to the influence of field position, game context, and teammate contribution. Net expected points (NEP) models quantify the change in win probability in points added by a player in a particular situation. Tracking models quantify a player's performance in certain domains. Our objective was to assess NFL performance following ACL reconstruction using expected points and tracking models that do not share the limitations of traditional statistics. We identified NFL players who sustained an ACL rupture and underwent surgical reconstruction between 2007 and 2022 using a publicly available database. We collected demographic and outcome data for one-year preinjury and two years postinjury. We excluded players without pre or postinjury data. Our primary outcome for offensive players was net expected points. Our primary outcome for defensive lineman was pass rush pressure rate, for defensive backs was passer rating when targeted, and for linebackers was average depth of tackle. Postinjury outcomes were compared with preinjury using a paired T test. We identified 205 eligible cases. Pre and postinjury outcome data are displayed in Table 1 and Table 2. Running backs had a significant decrease in yards per attempt, yards after contact per attempt, total NEP, and receiving NEP in the postinjury year one season (p=.049, .012, .010, .005 respectively). Pass catchers had a significant decline in receiving NEP in the postinjury year one season and in yards per reception, yards per route run, and yards after catch per reception two years post injury (p=.035, .021, .026, .015). Quarterbacks had a significant decline in NEP per rush two seasons postinjury(p=.019). There was no change in performance among linemen or defensive backs. There was a significant decrease in forced incompletion rate one year post injury in linebackers (p=.049). ACL ruptures are associated with decreased rushing, receiving, and pass rush performance in NFL players. There were no significant changes in coverage or run defense performance. For any figures or tables, please contact the authors directly.