Blunt trauma to the kidneys is the third most common solid organ to experience damage, after the spleen and the liver. It commonly occurs secondary to the blunt forces seen in a motor vehicle accident but can also occur in falls or sports injuries. When it occurs in sports injuries, it is due to blunt trauma from helmets or knees and shoulder pads. These injuries are often associated with football or soccer, martial arts or falls from all-terrain vehicles. In fact, these injuries are found in both individual and team sports. Some individual sports that can involve blunt trauma to the kidneys are commonly seen in cycling (the most common), winter sports, contact sports and horseback riding.
Initially, it was recommended by the American Academy of Pediatrics that children with only one kidney be spared from doing any sport that could damage the residual kidney. A study on 45,000 kids with kidney injuries, however, resulted in findings that showed no kidney loss was ever demonstrated after blunt trauma in sports. They have since changed their recommendation. An exception to this, is sledding, skiing and rollerblading as these did have injuries that resulted in kidney loss.
Another study looked at a cohort of students from 1995 through 1997. They documented 4.4 million athlete exposures to games and practices. There were only 12 injuries in football and 2 injuries with girls’ soccer playing. The American Academy of Pediatrics has since said “a qualified yes” to students who want to play sports but have a single kidney. Some physicians, however, disagree.
When an injury to the kidneys happens, the first sign is pain in the kidney area, followed by shock, and followed again by gross hematuria. Some sufferers can exhibit microscopic hematuria as their only finding of blunt trauma to the kidneys. There is a greater likelihood of a serious injury to the kidneys during a traffic crash as opposed to a sports injury.
The best way to see if a blunt trauma injury has happened to the kidneys is to do a contrast enhanced CT scan of the abdomen. This test will also reveal the presence of other blunt trauma injuries, including those to a viscus, or to the gallbladder, liver and spleen. An ultrasound examination can be done but this is less effective in finding these type of injuries when compared to CT scan.
The treatment of blunt trauma to the kidney usually is conservative management with intravenous fluids, watchful waiting and close monitoring. This doesn’t apply in conditions where there is urinary extravasation into the abdomen or retroperitoneal space or if there are injuries to other parts of the abdomen. If some of the kidney gets devitalized, it should be removed surgically. When there is multiple abdominal trauma, complications are likely and surgery is usually the best option. Even so, most cases do well with watchful waiting.
Another study showed that kidney trauma is most commonly associated with blunt trauma to other abdominal organs, including the spleen and liver, which sit close to the kidneys. The kidney trauma is usually less severe than the trauma to other organs so there may be a surgery intervention that has nothing to do with the kidney aspect of the problem.