Your spine is composed of a stack of bones called vertebrae. They protect your spinal cord. A Jefferson fracture is another name for a bone fracture of the front and back arches of the C1 vertebra. The C1 vertebra is the top one, closest to your skull.

C1 fractures represent about 2 percent of all vertebral fractures, according to a 2013 review. Vertebral fractures are the most common fractures related to osteoporosis.

A Jefferson fracture causes upper neck pain. You may not have any problems with movement, speech, or brain function unless nerves in the spinal cord are also injured.

In some cases, there’s damage to the arteries in the neck. Injuries to blood vessels in the upper neck can lead to neurological complications, such as ataxia. Ataxia is a loss of muscle control and balance while walking. A bruise and swelling around the injury site are common.

You can distinguish a Jefferson fracture from another cervical (neck) injury by noting where you have symptoms:

  • There may be pain and stiffness, usually isolated to the area around the fractured vertebra.
  • You may have trouble walking and even breathing if there’s been spinal cord damage.
  • You may feel a lot of pain in another part of the body and not be aware of your neck pain.

Pain that radiates down your spine and into your legs most likely comes from a disc in your spine pressing against the spinal cord, not from a Jefferson fracture.

A Jefferson fracture is often caused by trauma to the back of the head. The contact makes the neck violently snap back or forward, cracking the ring-shaped C1.

Divers are at high risk of getting this fracture. Hitting water with the back of the head can be quite dangerous. Anyone who plays contact sports is also at a higher risk.

Another common cause is a car accident. A driver or passenger who hits the top of the car could get a fracture to the C1 or other upper vertebrae.

People with osteoporosis are also a higher risk for fracturing the C1 or any of the bones in the vertebrae.

Your doctor will review your medical history and your symptoms. Then, they’ll perform a gentle physical examination of your neck, as there may be swelling and bruising from the injury.

An X-ray can help determine the size and location of the fracture. Your doctor may also order a CT scan to see if the vertebra has shifted out of alignment.

A CT scan is a special type of X-ray that uses computer technology to create cross-sectional slices of the area being scanned. These highly detailed images can also reveal ligament damage and other injuries to soft tissue.

If you have neck pain — even if it doesn’t seem too severe — tell your doctor. Ignoring neck pain after an accident or other injury may lead to further injury.

Your treatment plan will depend on the nature of the fracture. A key part of the injury is damage to the transverse ligament. The transverse ligament is a thick band that helps stabilize the C1 in the neck. Surgery may be necessary if the ligament is badly torn.

You may also be able to lie in traction with a device called a halo around your head and neck to keep you from moving. The halo is kept in place with pins placed into your skull.

Less severe fractures may be stabilized by a neck brace.

A C1 break can be very unstable. Surgery is often necessary to stabilize the vertebrae and prevent further damage. A procedure called surgical decompression may be performed. It involves removing bone chips and fragments from the vertebrae to help make sure nothing interferes with the healing of the C1 or that anything presses on the nerves.

If surgery is needed, recovery will likely take about 12 weeks. This is regardless of the type of surgery. If the fracture is minor, you may be able to get by with wearing a neck brace for six to eight weeks. A more serious case could require surgery and then a couple of months in traction.

Avoid lifting anything heavy during recovery. You should also avoid activities in which your neck can be reinjured, such as diving or contact sports. You may be able to avoid any long-term limitations or complications if your surgery was successful and you followed your doctor’s advice.

If the C1 is fused to the C2 and C3 vertebrae below it, you may have slightly less flexibility in your neck. Incorporating physical therapy during your recovery should help you compensate.

Any injury to the spine is a serious matter. The most serious concern is damage to the spinal cord. If you’ve experienced a Jefferson fracture without any neurological problems, you should be able to achieve a full recovery. The key will be following your doctor’s advice every day.