Presentation
Motor vehicle collision, clinically unstable pelvis.
Patient Data
Widening right sacroiliac joint indicating ligament tears (anterior/posterior sacroiliac, sacrotuberous and sacrospinous) and widening of the symphysis pubis with superior displacement of the right hemipelvis.
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.
Case Discussion
The combination of sacroiliac joint and symphysis pubis disruption with superior displacement of the hemipelvis is indicative of a vertical shear injury using the Young and Burgess classification of pelvic ring injuries.