Blunt trauma accounts for more than 90% of renal injuries in children The majority result from motor vehicle accidents; falls, sports-related incidents, and direct blows are also common mechanisms of injury In these scenarios, the kidneys are crushed against the ribs or vertebral column from their relatively fixed position within Gerota fascia Injuries include contusions, renal lacerations, and rarely stretching of the vascular pedicle causing renal vein or artery injuries Penetrating trauma accounts for the 10% of remaining cases Approximately 10% of penetrating abdominal injuries involve the kidney Minor renal injuries account for 85% of total injuries, lacerations in 10%, and severe kidney ruptures, fractures of pedicle injuries in less than 5% of cases Associated extrarenal injuries often occur, with head injuries being the most common Associated intraperitoneal injuries occur in 80% of patients with penetrating renal trauma and 20% of patients with blunt renal trauma In general, the hospital length of stay is determined by the associated injuries and not the renal injuries Historically, pre-existing anomalies have been believed to increase the risk and severity of injury to the kidney Coincidental congenital renal anomalies and intrarenal tumors have been reported in up to 20% of children with renal injuries However, it appears that in most patients, congenital genitourinary anomalies associated with renal injury are incidental findings and not increase morbidity More accurate recent reviews show that the incidence rate is closer to 1% Nevertheless, a high index of suspicion should be maintained in any child who presents with gross hematuria after a relatively minor trauma Other patients may present with an acute abdomen due to intraperitoneal rupture of a hydronephrotic kidney Clinical Considerations Clinical Recognition Children who sustain significant renal injuries usually present with localized signs such as flank tenderness, hematoma, palpable mass, or ecchymosis However, since kidney injuries are often associated with injuries to other organs, generalized abdominal tenderness, rigidity of the abdominal wall, paralytic ileus, and hypovolemic shock may all be part of the clinical picture Penetrating injuries to the chest, abdomen, flank, and lumbar regions should alert the clinician to the possibility of a renal injury Hematuria has long been considered the cardinal marker of renal injury and 98% of pediatric patients suffering a renal injury will have some degree of hematuria However, the degree of hematuria does not correlate with the severity