AEMCA Practice Exam

Which type of injury is characterized by the spine experiencing flexion and distraction forces?

1. Compression fracture

2. Hangman's fracture

3. Chance fracture

4. Contusion injury

The correct answer is: Chance fracture

The type of injury that is characterized by the spine experiencing flexion and distraction forces is best identified as a Chance fracture. This injury typically occurs due to a mechanism involving a combination of flexion, such as during a sudden forward bending movement, and distraction, which refers to forces that pull apart the spinal segments. Chance fractures are often seen in situations like motor vehicle accidents or falls where the body is thrown forward while the pelvis remains secure, leading to hyperflexion of the spine. This results in a transverse fracture of the vertebra, usually at the lumbar region, and may affect the posterior element as well, indicating significant instability. In contrast, other types of injuries mentioned have different mechanisms of occurrence. Compression fractures occur due to axial loading on the spine, commonly seen in osteoporosis or trauma. Hangman's fractures result from hyperextension of the neck, often associated with a hanging mechanism or severe deceleration injury. Contusion injuries, on the other hand, are more about bruising of tissues rather than a specific structural type of fracture in the spinal region. Understanding these distinctions clarifies why Chance fracture fits the description of being associated with flexion and distraction forces.