What is a Burst (Axial) Fracture of the Spine?

Orthopaedic & Spine Center

Mark W. McFarland, MD

One of the first things you learn in medical school is that human bones can withstand lots of punishment, but they also can break in a lot of different ways.  Spinal bones (vertebrae) tend to break in specific ways, and some can be more serious than others.  In this article, I’m going to discuss the burst fracture of the spine, how it is commonly caused, diagnosed and treated.

Based on how they are shaped, their position in the body, and typically, how force is applied to them, the vertebrae in the spine tend to fracture from compression.  This can happen through trauma from sports, a motor vehicle accident, a fall, gunshot wound, or some other injury where force is placed upon the spinal bones that causes one of more of them to be compressed beyond their peak load capacity. Rarely, a burst fracture can be caused by a lesser trauma in a patient whose spinal bones have been compromised/weakened by cancer or osteoporosis.

In a simple, less severe compression fracture of the vertebral body, the bone may be fractured in a few places, but remain relatively intact.  The more compression that is applied to the bone, the more fracturing takes place and the bone may break or “burst” in multiple directions.  Typically, during a burst fracture, the cylindrical part of the vertebral column or body, shatters.  As this part of the vertebrae provides the main structure and stability to that portion of the spine, instability instantly occurs.  Bone fragments often can injure the spinal cord or nerve roots, leading to severe pain, numbness, weakness and loss of bladder or bowel function.  This type of spinal fracture is a true emergency and must be seen to immediately.

Typically, this type of injured patient will be taken to the ER immediately for evaluation.  X-rays and a CT scan will be ordered to ascertain the extent of the injury and fractures to the spinal bones and an MR scan will be ordered to evaluate the injuries to the spinal cord and nerve roots.

Treatment will depend on if the patient has been neurologically compromised and/or if there are structural problems, such as instability of the spine, that must be fixed.  As burst fractures of the vertebrae tend to cause stability issues, I often must perform a surgical procedure to stabilize the spine, so that the patient will be able to walk and stand upright.  That often will be a spinal fusion procedure, where I will use rods, plates, and screws to stabilize the spine.  If the bones have broken and moved into the spinal canal or have impinged on the nerve roots, I must remove those fragments to allow the nerves to heal and function properly.  That could mean a laminectomy, removing the lamina or a corpectomy, removing the vertebral body itself.

Typically, patients without neurologic issues who only had instability will be able to have surgery and go home the same or next day. Those with neurologic issues may or may not resolve immediately or soon after surgery and some may have to transition to a rehabilitation facility to await further healing and have physical therapy while they recover. For those patients who head home quickly, I typically refer them to physical therapy in the home and then as an outpatient, so that they learn to build their strength and range of motion as quickly as possible.  Thankfully, most patients will recover function and regain strength and can return to their normal lives and activities after fully healing, which can take up to a year.