Chance Fracture

Chance Fracture

Described by G.Q. Chance in 1948, a fracture that results in a horizontal splitting of the vertebra that begins with the spinous process or lamina and extends anteriorly through the pedicles and vertebral body which tends to have a wedge compression fracture, while the posterior elements of the vertebra are distracted. Despite the extent of damage to the vertebra, these fractures tend to be stable. They are most common in T12, L1, and L2—the thoracolumbar spine—the junction of the relatively rigid thoracic spine and the more flexible lumbar spine. They were known as 'seat-belt' fractures with the advent of lap seat belts in cars, but are rare as cars are now fitted with shoulder/lap belt combinations. Most Chance fractures seen today are from falls or crush type injuries in which the thorax is acutely hyperflexed. About 50% of Chance fractures have associated intraabdominal injuries, fractures of the pancreas, duodenum and mesentery contusions or rupture which must be surgically assessed