Epidemiology and Outcomes of Ankle Injuries in the National Football League.

BACKGROUND

Traumatic ankle injuries are commonly complicated by persistent symptoms and the development of chronic ankle instability.

PURPOSE

To describe the epidemiology of ankle injuries in the National Football League (NFL) and investigate the effects that ankle injuries have on performance metrics in the years after injury.

STUDY DESIGN

Descriptive epidemiologic study.

METHODS

Ankle injuries sustained by NFL players during the 2015-2016, 2016-2017, and 2017-2018 seasons were identified using the Pro Football Reference database. Cumulative incidence was calculated, and demographic identifiers were collected for each injury. The return-to-play (RTP) rate was also recorded. For each player who met inclusion for the performance analysis, power rating (PR) was calculated for the preinjury season (Y-1) and 2 postinjury seasons (Y+1 and Y+2) as follows: = (/10) + ( × 6) + (s) + ( × 2) + ( × 2). Mean PRs were calculated for each season as well as the percentage change and mean difference in PR between Y-1 and Y+1 (ΔPR%, ΔPR) and between Y-1 and Y+2 (ΔPR%, ΔPR). Subgroup analyses of PR were performed by player position, injury type, and years of experience.

RESULTS

Overall, 668 ankle injuries were identified, with an average cumulative incidence across the 3 seasons of 11.2% and RTP rate of 91%. Of those injuries, 159 met inclusion criteria for the PR analysis. The mean overall PR (96.95 in Y-1) declined 22% in Y+1 to 76.10 (-20.85 [95% CI, -13.82 to -27.89]; < .001) and 27% in Y+2 to 70.93 (-26.02 [95% CI, -18.04 to -34.00]; < .001). The mean PR per game played (6.70 in Y-1) decreased 14% in Y+1 to 5.75 (-0.95 [95% CI, -0.56 to -1.34]; < .001) and 17% in Y+2 to 5.54 (-1.16 [95% CI, -0.63 to -1.62]; < .001).

CONCLUSION

It was found that ankle injuries hampered the performance of NFL players, even multiple years after the injury occurred, despite a relatively high RTP rate. There was a decrease in total games played after ankle injuries as well as a decreased performance output per game played.