Knee Ligament Injuries in the National Football League: Impact of Field Surface Type During the 2020-2023 Seasons

Introduction A subject of ongoing debate within the National Football League (NFL) community revolves around the comparative risk of anterior cruciate ligament (ACL) injuries on natural versus artificial turf field surfaces. There have been mixed results as to whether there is a difference in injury rates depending on the playing surface and what factors might play a role in affecting these rates. Methods This study aims to compare the incidence of in-game knee ligament tears in the NFL during the 2020-2023 seasons. Data was collected from publicly available resources to determine and classify specific injury characteristics such as ligament, injury date, location, and field surface type. Only in-game knee ligament tears, including those occurring in pre-season games, were included. Significance was determined using two-sample T-tests. Results Over the 2020, 2021, 2022, and 2023 seasons, there were 149 ligament tears, with 58 occurring on natural turf (38.9%) and 91 occurring on artificial turf (61.1%). Over the course of the same four years, 1213 games were played, with 524 (43.2%) games on natural turf and 689 games on artificial turf (56.8%). Accounting for the number of games played on each surface, natural turf saw a rate of 0.111 knee ligament tears per game, while artificial turf saw 0.132 ligament tears per game. Conclusion Over the course of the study period, we determined that there was no significant difference between the rates of in-game knee ligament tears on natural and artificial turf playing surfaces. Our study shows that regardless of differences in composition and other playing surface features, there is ultimately no difference in the incidence of knee ligament tears. Playing surfaces should still be monitored and regulated, and the incidence of other injuries, such as concussions, as well as player preference, should be considered when considering the ideal surface.