What kinds of fracture are considered a critical injury?

Critical injury: Fractures that are considered critical would have an immediate affect on a persons life. This could be a fracture in the cervical spine, a fracture that tears a major blood vessel, a rib fracture that punctures a lung or a skull fracture.

Life-threatening: Any fracture that leads to the end-of-life would be a "critical injury". Mostly this includes spine or pelvic injuries. The spine injury is critical because its not only related to paralysis, but it usually is associated with other major injuries. Pelvic fractures are similar, but they also are related to injury of blood vessels that can lead to major hemorrhage (blood loss) and thus end-of-life.