Findings
- Widening and offset of the pubic symphysis and left sacroiliac joint with superior translation of the left hemipelvis
- Acute left sacral ala fracture with a superiorly displaced S1 fragment
- Acute comminuted right superior pubic ramus fracture and nondisplaced right inferior pubic ramus fracture
- Acute laterally distracted fracture of the left L5 transverse process
Diagnosis
Vertical shear pelvic ring injury
Sample Report
Acute unstable vertical shear pelvic ring injury with symphyseal and left sacroiliac joint diastasis, superior left hemipelvic translation, and fractures of the left sacral ala (with superiorly displaced S1 fragment), right superior (comminuted) and inferior pubic rami, and left L5 transverse process (laterally distracted).
No malalignment of the hips or right sacroiliac joint.
Discussion
- It is important to be able to recognize unstable pelvic injuries because this impacts immediate patient management (pelvic binders are typically placed before the patient even goes for CT imaging)
- The Young Burgess classification is the most commonly used system:
- Anterior-posterior compression (APC) - the pubic symphysis is the weak link, so it is affected first
- APC I: widening of the pubic symphysis < 2.5 cm
- Stable
- APC II: widening of the pubic symphysis > 2.5 cm, anterior sacroiliac joint widening
- Vertically stable, rotationally unstable
- APC III: widening of the pubic symphysis > 5 cm, widening of anterior and posterior sacroiliacs joints
- Globally unstable
- APC I: widening of the pubic symphysis < 2.5 cm
- Lateral compression - the obturator ring is the weak link, so it is affected first
- LC I: obturator ring fractures and sacral compression fractures
- Stable
- LC II: LC I + iliac crescent fracture
- Vertically stable, rotationally unstable
- LC III: LC I/II with a contralateral APC injury
- Globally unstable
- LC I: obturator ring fractures and sacral compression fractures
- Vertical shear - Vertical hemipelvis translation with offset of the pubic symphysis and sacroiliac joint
- Globally unstable
- Anterior-posterior compression (APC) - the pubic symphysis is the weak link, so it is affected first
Annotated Images & Illustrations
Widening and offset of the pubic symphysis (red arrow) and left sacroiliac joint (yellow arrow). Fractures of the right superior (white arrow) and inferior (gray arrow) pubic rami. Displaced fractures of the left sacral ala (blue arrow) and left L5 transverse process (black arrow).