Which fracture involves hyperextension as a mechanism of injury?

The correct answer is the Chance fracture, which is characterized by a mechanism of injury involving hyperextension. A Chance fracture typically occurs due to a significant forward bending motion that leads to a flexion-distraction injury of the spine. This mechanism often manifests as a result of high-energy trauma, such as in a motor vehicle accident where the torso is forcibly flexed forward while the lower spine remains relatively stable.

The Chance fracture is specifically categorized as a type of lumbar spine injury that results in a split through the vertebra from front to back due to this hyperextension mechanism. As such, it can critically impact the spinal structures, necessitating careful assessment and precise management to ensure stability and proper healing.

Other types of fractures listed do not primarily involve hyperextension in their mechanism. Denis 1 fractures typically involve a stable compression injury, where the vertebra is compacted but not disrupted. Denis 2 fractures are related to injury involving the posterior column, usually not associated with hyperextension. Compression fractures often result from axial loading rather than hyperextension forces. The distinction in mechanisms highlights why the Chance fracture specifically relates to hyperextension injuries.