Occult extraperitoneal rectal injury and necrotizing fasciitis of the thigh following traumatic pelvic fracture: case report

Abstract

Extraperitoneal rectal injuries following blunt trauma are rare and often difficult to diagnose. In the setting of pelvic fractures, these injuries may be missed on initial imaging, leading to severe complications. We report a 40-year-old male who sustained a pelvic crush injury. Computed tomography (CT) demonstrated complex pelvic fractures with no evidence of rectal injury. Subtle extraperitoneal perirectal air was identified on further imaging. On day 13, he developed sepsis without an obvious source. Repeat CT revealed an extraperitoneal rectal perforation with extensive air tracking into the pelvic soft tissues and thigh. The patient underwent emergent surgical intervention including loop colostomy, proctoscopy, and extensive debridement for necrotizing soft tissue infection (NF). He subsequently improved with staged debridement and negative pressure wound therapy. This case highlights the diagnostic challenges of occult extraperitoneal rectal injuries. Unexplained extraperitoneal air should prompt further evaluation with endoscopy. Delayed diagnosis resulted in life-threatening complications e.g. NF.