CASE 22 pelvic ring injuries

                          

 

A 45-year-old cyclist arrives to the trauma bay after being hit by a motor vehicle while crossing a highway earlier in the evening. The patient is awake but somnolent

in the trauma bay. Your examination does not reveal any open wounds or gross deformity about the extremities. An AP pelvis and CT imaging reveal a lateral compression Type II (LC-II) pelvic ring injury. Based on the mechanism of injury and described Young–Burgess injury classification type.

Which answer best describes the radiographic finding most likely associated with this patient’s injury?

1. Impacted sacral alar fracture and ipsilateral superior and inferior ramus fractures

2. Pubic symphysis diastasis greater than 2.5 cm with external rotation of either hemipelvis and anterior sacroiliac joint widening

3. Superior and inferior ramus fractures with ipsilateral posterior ilium fracture

4. Superior and inferior ramus fractures with ipsilateral sacral compression fracture and external rotation of the contralateral hemipelvis

Discussion

The correct answer is (C). The described LC-II injury involves ipsilateral ramus and ilium crescent fractures as described above. Choices A, B, and D represent Young–Burgess LC-I, APC-II, and LC-III type injuries, respectively.

The decision is made to stabilize the patients pelvic ring injury with a temporary external fixator.

Which construct will is best suited to resist further internal rotation of the patient’s hemipelvis?

1. Anterior external fixator with dual 4-mm pins placed in bilateral iliac crests

2. Anterior external fixator with parallel supra-acetabular pins

3. Anterior hybrid construct (supra-acetabular and iliac crest pins)

4. Anterior external fixator with single 5-mm pins placed in bilateral iliac crests

 

Discussion

The correct answer is (B). Archdeacon et al. demonstrated in their 2009 biomechanical analysis that despite the superior resistance to flexion and extension provided by hybrid frames, supra-acetabular constructs were superior in resisting internal/external rotation of the hemipelvis.

What is the most likely cause of mortality due to an associated injury given this patient’s pelvic ring fracture morphology?

1. Pelvic and abdominal visceral injury

2. Thoracic injury

3. Distal extremity vascular injury

4. Closed head injury

 

Discussion

The correct answer is (D). Closed head injury is the most common cause of death with this patient’s injury pattern. Pelvic and abdominal viscera injuries are related to patient mortality following APC type injuries.

 

Objectives: Did you learn...?

 

 

The Young–Burgess classification of pelvic ring injuries (LC)? Associated injuries in patients with pelvic ring injuries?