Odontoid Fracture

What it is

The odontoid (also called the dens) is a peg of bone that rises from the second neck vertebra (C2) and acts as the pivot the head turns on. An odontoid fracture is a break in that peg. In older adults it often happens from a simple fall, because the bone has weakened; in younger people it usually takes a higher-energy injury like a car crash. It is one of the more common fractures of the upper neck.

The three types

Where the break sits matters, because it predicts how well it will heal:

• Type I: a break at the very tip. Uncommon and usually stable.
• Type II: a break across the narrow waist where the peg meets the body of C2. This is the most common type and the hardest to heal, because blood supply there is limited.
• Type III: a break that extends down into the body of C2. Because that bone has a richer blood supply, it tends to heal well, often in a brace.

How we diagnose and treat it

X-rays and a CT scan show the fracture and its type, and an MRI checks the spinal cord and ligaments. Many fractures, especially Type III and stable Type I, heal with a rigid collar or, occasionally, a halo. A Type II fracture is the one most likely to need surgery to bring the pieces together and hold them, either with a screw placed up through the peg or by fusing C1 to C2. We choose based on your fracture, your bone quality, and your overall health.

The science: for the curious

The reason Type II fractures get so much attention is their tendency not to knit on their own: the slender waist of the peg simply does not heal as reliably as bone with a better blood supply. That does not automatically mean surgery: in many older adults, a well-fitted collar and close follow-up are a reasonable path, accepting that the bone may form a sturdy fibrous union rather than a bony one. The right answer balances the chance of healing against the risks of an operation for you specifically, which is exactly the conversation we will have.

Learn more

OrthoInfo, Neck Pain: orthoinfo.aaos.org (opens in a new tab)

OrthoInfo, Osteoporosis and Spinal Fractures: orthoinfo.aaos.org (opens in a new tab)

This handout is general education about a common condition and does not replace the personalized advice we discuss in clinic. If anything here does not match what we talked about, what we talked about wins: please ask me.