Chance fracture

Chance fractures are pure bony injuries that extend all the way through the spinal column: from posterior to anterior through the spinous process, pedicles, and vertebral body, respectively. 

Pathology

Mechanism

They tend to occur from a flexion-distraction type injury ¹. The most common history is that of a back seat passenger restrained by a lap seatbelt and involved in a motor vehicle accident or that of a person who has fallen from a height. The middle and posterior columns are typically disrupted.

Location

This fracture most commonly occurs about the upper lumbar spine (with the thoracolumbar junction accounting for ~50% of cases ³), but it may be observed in the midlumbar region in children.

Associated injuries

There is a high incidence of associated intra-abdominal injuries (i.e. pancreatic, duodenal) that can result in increased morbidity and mortality. Associated intra-abdominal injuries appear to be more common in the pediatric age group with incidence approaching 50%.

If unrecognized, Chance injuries may result in progressive kyphosis with resulting pain and deformity.

Radiographic features

Plain film

Features include

• empty vertebral bodysign:  can be seen on an AP radiograph and results from the vertical separation of the posterior elements displacing the spinous processes or spinous process fracture fragments off the vertebral body on the AP projection
• horizontal fracture through one or both pedicles
• widening of the interpedicular distance: often suggests a burst component
• transverse fractures across the transverse processes, laminae, and articular processes
• widening of the facet joints and increased intercostal spacing

CT

More accurately delineates fracture details.

Treatment

The fractures generally can be reduced by placing the patient on a Risser table with hyperextension applied to the thoracolumbar junction prior to applying a fiberglass or plaster cast.

If immobilization is impractical (large body habitus) or the patient has polytrauma, surgical management may be indicated. 

EtymologyHistorical context

It is named after George Quentin Chance, British radiologist who first described it in 1948 ².