A Combined Bony and Soft Tissue, Thoracic Chance Fracture: Late Displacement following Conservative Treatment.

We report the first case of a combined bony and soft tissue Chance fracture in the thoracic spine, with late presenting displacement following conservative management. Chance fractures are flexion-distraction injuries to the spine. They consist of disruption and longitudinal separation of the posterior elements of the vertebra, with the fracture extending through the pedicles and into the vertebral body. Both bony and soft tissue Chance fractures of the lumbar spine have been reported, as well as bony Chance fractures in the thoracic spine. This case suggests that this type of fracture is unstable and is an indication for operative management. It is also important to note that the displacement of the fracture occurred at more than eight weeks after injury, suggesting that instability may not present immediately.