Classification scheme for pelvic fragility fractures^[1]

The pictures above depict the four basic categories of fragility pelvis fractures. Fracture displacement is the key feature that distinguish between Types I and II from Types III and IV. The wide red lines separated by white indicate displaced fractures. The basic categories are defined as follows:

Type I: Anterior ring disruption, either unilateral or bilateral

Type II: Non-displaced posterior injuries

Type III: Displaced unilateral posterior injury with an anterior pelvic ring injury

Type IV: Displaced bilateral posterior injuries.