Superior gluteal artery injury presenting as delayed onset shock.

Injury to the superior gluteal artery (SGA) is usually associated with acetabular fractures or posterior pelvic ring injuries. The diagnosis is suspected in cases of initial hemodynamic instability which is refractory to resuscitation. The initial presentation is often dramatic and is caused by direct injury to the artery at the time of traumatic impact. In these cases, patient management at most trauma centers follows a pre-arranged algorithm which decreases the likelihood of a missed diagnosis. Delayed arterial bleeding, however, is rare and potentially catastrophic since most algorithms are not designed to detect these infrequent occurrences. We present two such cases due to initial blunt buttock trauma combined with an anterior pelvic ring fracture and a L2 spine fracture which resulted in delayed massive bleeding from the SGA. Delayed arterial bleeding should be considered in late onset shock associated with pelvic or lumbar vertebrae body fractures or direct buttock injury. If active bleeding is suspected, urgent arteriography with embolization is the treatment of choice.