| LC: anterior injury = rami fractures |
| LC I: sacral fracture on side of impact |
| LC II: crescent fracture on side of impact |
| LC III: type I or II injury on side of impact with contralateral open book injury |
| AP compression (APC): anterior injury = symphysis diastasis/rami fractures |
| APC I: minor opening of symphysis and SI joint anteriorly |
| APC II: opening of anterior SI, intact posterior SI ligaments |
| APC III: complete disruption of SI joint |
| Vertical shear (VS) type: |
| Vertical displacement of hemipelvis with symphysis diastasis or rami fractures anteriorly, iliac wing, sacral facture, or SI dislocation posteriorly |
| Combined mechanism (CM) type: any combination of above injuries |
