Which of the following statement is TRUE about crescent fracture?

When the posterior pelvic disruption passes through the lower poion of the sacroiliac joint and exits through the ilium, this is known as crescent fracture. A poion of the iliac wing remains attached to the sacrum by means of the sacro-iliac ligaments. The piece of bone fractured from the iliac wing resembles a crescentic moon, hence the term. The most common mechanism of injury is lateral compression, resulting in the wing being impinged against the dense sacral bone. These fractures are rotationally unstable, and are classified as lateral compression type II in the Young-Burgess classification system. Ref: Fractures of the Pelvis and Acetabulum edited by Wade R. Smith, Bruce H. Ziran, Steven J Morgan, 2007, Page 112.