Diagram
What is the radiographic hallmark of a vertical shear injury?
Superior displacement of an innominate bone relative to the rest of the pelvis.
Vertical shear injuries most commonly occur following a fall from a height onto the lower extremities, resulting in upward displacement of one innominate bone relative to the rest of the pelvis. Fractures or ligament disruption may uncouple the displaced innominate bone from the remaining pelvis. In this case, the disruption was ligamentous: in the accompanying illustration, ligamentous injury is symbolized by coloring the ligaments red.
If you'd like to look at better diagrams of pelvic fractures, click here.
If you'd like to look at an example of a lateral compression fracture, click here.
If you'd like to look at an example of an anteroposterior compression fracture, click here.