Unilateral complete disruption of posterior arch through sacrum

This is classified as an AO/OTA 61C1.3 injury.

Posterior injury
The posterior injury is a completely unstable vertical fracture through the sacrum.

Anterior injury

Anterior injury is one or more of the following:

• Symphyseal disruption
• Pubis (uni/bilateral, ipsi/contralateral)
• Ramus (uni/bilateral, ipsi/contralateral)