Sports participation and high grade renal injuries in children.

PURPOSE: The risk of major renal injury resulting from various forms of sports participation is unknown. Urologists often recommend that children with a solitary kidney avoid contact sports. We reviewed our recent experience with pediatric renal trauma to determine if there is an association between different types of sports activity and high grade renal injury.
MATERIALS AND METHODS: We retrospectively reviewed the medical records of 68 consecutive children with blunt renal injury who were treated at 2 level I trauma centers. Injuries were graded using the renal injury scale of the American Association for the Surgery of Trauma. Records were reviewed for mechanism of injury, associated injuries, management and injury severity score. Statistical analysis was performed using Fisher's exact test or Wilcoxon rank sum test.
RESULTS: Of the 68 renal lesions 13 were grade I, 15 grade II, 15 grade III, 17 grade IV and 8 grade V. The most common cause of renal trauma was motor vehicle accidents, accounting for 21 injuries (30.1%). Accidents associated with nonmotorized sports activity accounted for 14 injuries (20.6%). Bicycle riding was the most common sports etiology, accounting for 8 of 14 cases (57.1%) at an age range of 5 to 15 years (mean 9.4). None of the bicycle injuries involved collision with a motor vehicle. Bicycling accounted for 1 grade I, 1 grade II, 1 grade III, 2 grade IV and 3 grade V injuries. Football, hockey and sledding were responsible for the remaining 6 sports related injuries. High grade renal injury (grade IV or V) was identified in 5 of 8 bicycle accidents (62.5%) and 1 of 6 nonbicycle sports related injuries (16.7%, p = 0.14). Injury severity scores ranged from 4 to 50 (mean 20.6) for bicycle renal injuries and 4 to 13 (mean 6.7) for nonbicycle sports related trauma (p <0.05). Parents indicated that blunt trauma from the handlebars was the major factor contributing to renal injury in 3 bicycle cases. Renal trauma from bicycle riding resulted in 1 nephrectomy.
CONCLUSIONS: Bicycle riding is the most common sports related cause of renal injury in children and is associated with a significant risk of major renal injury. Families of children with a solitary kidney should be aware of this risk factor. Team contact sports are an uncommon cause of high grade renal injury. Current recommendations regarding sports participation by children with a solitary kidney need to be reevaluated.