Kidney injuries in professional American football: implications for management of an athlete with 1 functioning kidney.

BACKGROUND The frequency and severity of kidney injuries and their impact on return to play in American football has not been described in the literature. PURPOSE Our objective is to identify the number of kidney injuries in the National Football League (NFL) and the effect of these injuries. STUDY DESIGN Case series; Level of evidence, 4. METHODS All kidney injuries in the NFL from 1986 to 2004 were reviewed, including the type and mechanism of injury, treatment, and time to return to play. In addition, NFL physicians and athletic trainers were asked if they were aware of any football player at the professional, collegiate, or high school levels who had lost a kidney and how they would advise a football player with only 1 functioning kidney. RESULTS A total of 52 cases of renal injuries were identified, an average of 2.7 cases per season. The rate of kidney injury was 10 times greater during games (0.000055 per exposure) than practices (0.000005 per exposure) (P < .0001). The most common injury was kidney contusion (42), followed by kidney laceration (6) and kidney stones and dysfunction (2 each). Almost all the injuries were contact related (49). More than a third of the players required hospitalization for their injury (18), although none required surgery. All the athletes returned to play. The most days missed were after a kidney laceration (mean, 59.8), followed by kidney contusion (15.1) and dysfunction (14.0). While 61% of respondents would allow a professional athlete with only 1 kidney to play, approximately 50% would advise a college athlete with only 1 functioning kidney not to play football, and 60% would advise a similar high school athlete not to play. CONCLUSION Renal trauma is a rare but potentially debilitating injury in the NFL, with players at greater risk during games. Most players recover to play, but it may take some time, especially with a kidney laceration. It may be safe for players with only 1 functioning kidney to play in the NFL.