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

OrthoInfo — Osteoporosis and Spinal Fractures: orthoinfo.aaos.org

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.