Factors related to return to play after knee injury in high school football athletes.

PURPOSE: American football is played by over 1 million high school athletes in the United States, and knee injuries are the third most common injury. The purpose of this study is to identify factors that influence return to play after knee injuries in high school football athletes and whether return to play differs for varsity and nonvarsity football players. METHODS: We used academic year 2006-2007 through 2009-2010 data from the National High School Sports-Related Injury Surveillance Study. Polytomous logistic regression was used to assess factors influencing return to play. RESULTS: Thirty-one percent returned to play in more than 3 weeks or not at all. After adjusting for injury severity, a difference in time to return to play persisted for injuries occurring in the regular or postseason compared to pre-season (OR 0.5, CI: 0.3-0.9), and injuries occurring to varsity players compared with nonvarsity players (OR 0.7, CI: 0.4-1.0). CONCLUSIONS: Time in season, method of injury assessment, and the need for surgery were the main predictors of return to play for football athletes. As more factors were influential for varsity athletes than nonvarsity athletes, future studies should separate the groups of athletes to better identify their specific factors for time to return.