There are many different types of spinal fractures: Compression, Burst, Flexion-distraction, and Fracture-dislocation. Each of these types of fractures are described. Other terms your doctor may use to describe a fracture include stable, unstable, minor, and/or major.
Compression Fracture: This type of fracture is very common in patients with osteoporosis, or patients whose bones have been weakened by other diseases (such as bone cancer). The vertebra can absorb so much pressure; if there’s a sudden force of a lot of pressure, the bone may not be able to handle the stress. The vertebra can fracture then.
A wedge fracture is a subtype of compression fracture. With a wedge fracture, part of the vertebra—usually the anterior (front) part—collapses under pressure and becomes wedge shaped.
Burst Fracture: Burst fractures (see image below) are caused by severe trauma (eg, car accident). They happen when the vertebra is essentially crushed by extreme forces. Unlike compression fractures, it’s not just one part of the vertebra that’s fractured. In a burst fracture, the vertebra is fractured in multiple places. Because the vertebra is crushed completely, bony fragments can spread out and cause spinal cord injury. Burst fractures are more severe than compression fractures.
Flexion-distraction Fractures: If you’re in a car accident where your body is pushed forward, you may get a flexion-distraction fracture. Your spine is made to flex forward, but if there’s a sudden forward movement that places incredible stress on the spine, it may break a vertebra or vertebrae. Thinking of the three-column concept, a flexion-distraction fracture usually has fractures in the posterior and middle column. An example of a flexion-distraction fracture is below.
Stable and Unstable Fractures
Stable fractures don’t cause spinal deformity or neurologic (nerve) problems. With a stable fracture, the spine can still carry and distribute your weight pretty well (not as well as if there weren’t a fracture, but it’s still able to function with a stable fracture).
Unstable fractures make it difficult for the spine to carry and distribute weight. Unstable fractures have a chance of progressing and causing further damage. They may also cause spinal deformity.
Major and Minor Fractures
Minor fracture means a part of the posterior (back side) elements of the vertebra has broken—parts of the spine that are not as important to spinal column stability, or stability at the fractured level. The posterior elements include the spinous process and the facet joints (also called the articular processes). If you fracture this part of the vertebrae, it’s usually not too serious.
Major fracture means that part of the vertebral body, the pedicles, or the lamina has fractured. Fracturing the vertebral body is considered major because it helps carry so much weight and distribute the force of your movements. If it’s broken, you can have serious problems with the vertebrae lining up correctly. Fracturing the pedicles or lamina is dangerous because of the increased possibility of nerve damage. Additionally, the pedicles and lamina provide a lot of necessary support to keep your spine stable. If they fracture, your spine may be unstable.