Bilateral sacroiliac joint dislocation with intrapelvic intrusion of the intact lumbosacral spine and sacrum.

Two cases of bilateral sacroiliac joint dislocation with intrapelvic intrusion of the intact lumbosacral spine and sacrum are reported. This condition is a distinct traumatic entity. The essential features of this condition are the disruption of the pelvic ring with bilateral sacroiliac dislocation. The spine as a whole descends into the depths of the pelvis. Disruption of the anterior structures but not always the pubic symphysis is apparently a prerequisite for the development of the condition. Extensive soft-tissue damage is part of the injury. The etiology is a direct crushing violence to a standing or walking patient. It is assumed that this injury is less rare than it seems, and that the main reason for not being mentioned is the rarity of the survival of the patients. As a result of success in the intensive care of the severly injured, more survivals and more reports are anticipated.