Neil Osterweil

May 27, 2014

ORLANDO, Florida — Boxers are not the only athletes who take blows to the kidneys; recreational athletes such as cyclists, skiers, and snowboarders can also sustain isolated high-grade renal trauma, investigators have found.

Emergency department clinicians and surgeons should be aware that patients who sustain a sports-related injury might have high-grade renal trauma in the absence of injury to other organ systems, said Jeffrey Redshaw, MD, a research fellow in the division of Urology at the University of Utah School of Medicine in Salt Lake City.

Dr. Redshaw presented results from the retrospective study here at the American Urological Association (AUA) 2014 Annual Scientific Meeting.

To test their hypothesis that sports-related renal trauma can produce high-grade renal injuries not associated with polytrauma, Dr. Redshaw and his colleagues conducted a retrospective review of adult patients treated for renal trauma at their center from 2005 to 2011.

Injuries were categorized as being related or unrelated to sports. Renal trauma sustained during a sporting activity but caused by a nonsport event, such as a bicyclist being struck by a car or a skier colliding with a snowmobile, was counted as a nonsport injury.

The researchers identified 138 patients with a grade III to V injury on the American Association for the Surgery of Trauma (AAST) kidney injury scale; 42 were sports-related and 96 were not.

Overall, men were more likely than women to sustain kidney injuries (61.1 vs 38.9; P < .001). In particular, men were more likely to sustain sports-related injuries (90.5 vs 9.5; P < .001), possibly because of their testosterone-fueled aggression and risk-taking activities, said Dr. Redshaw

Sports Injuries Less Severe

Sports injuries, in general, were less severe than nonsports injuries. Grade III injuries were more often sports injuries than nonsports injuries (57.9% vs 49.4%), as were grade IV injuries (39.5% vs 31.3%).

However, grade V injuries were significantly less likely to be related to sports (2.6% vs 19.3%; P = .05).

In addition, mean injury severity score was lower for sports injuries than for nonsports injuries (12.6 vs 27.3; P < .001), and sports-injured patients were more hemodynamically stable.

Table. Outcomes by Type of Injury

Outcome Sports Injury Nonsports Injury P Value
Mean days in hospital 2.3 8.07 <.001
ICU admission 71.0% 88.0% .024
Intervention 11.9% 20.0% NS
Nephrectomy 0.0% 8.8% .018
Transfusion within 24 hours of admission 2.4% 41.0% <.001
Tachycardia 31.0% 63.2% .001
Injury to other solid organs 22.5% 64.1% <.001
Death 0.0% 14.7% .005


Most of the sports injuries were caused by blunt force trauma to the flanks, said senior investigator Jeremy Myers, MD, assistant professor of surgery at the University of Utah.

"At first I had assumed that the patients were injured with, say, a ski pole or tree branch going into the abdomen and puncturing or smashing the kidney. But in reality, it's a deceleration injury, with someone coming down onto the ground very hard on their back or their flank," he said.

This study is important because it brings to light the frequency of this type of injury, said Jack McAninch, MD, professor of urology at the University of California, San Francisco, and a past president of the AUA.

"In the entire state of Utah, a third of these patients had sports-related injuries, instead of from motor vehicle accidents or some other kind of injury. It's very unusual to have that kind of a distribution," he said.

He noted that a European study of ski-related injuries in Austria and in France showed similar results.

The study was internally funded. Dr. Redshaw, Dr. Myers, and Dr. McAninch have disclosed no relevant financial relationships.

American Urological Association (AUA) 2014 Annual Scientific Meeting. Abstract MP3-03. Presented May 16, 2014.


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