Athletes with a prior injury are more likely to experience another injury. Not a big surprise. Each injury increases the risk for further injury. The risk is about 1.5x the normal rate.
Repeat injuries are usually more severe.
The baseline risk of injury varies based on the sport. Football has the highest rate (9 injuries per 1,000 practices and 35 per 1,000 games).
Lehr ME, Plisky PJ, Butler RJ, Fink ML, Kiesel KB, Underwood FB. Field-expedient screening and injury risk algorithm categories as predictors of noncontact lower extremity injury. Scand J Med Sci Sports. 2013;23(4):e225-e232.
Dick R, Ferrara MS, Agel J, . Descriptive epidemiology of collegiate men’s football injuries: National Collegiate Athletic Association Injury Surveillance System, 1988-1989 through 2003-2004. J Athl Train. 2007;42(2):221-233.