Type III odontoid fracture

Case contributed by Dayu Gai
Diagnosis certain


This 74 year old lady was the passenger in a car accident moving at 40km/hour. A CT C-spine was performed and is shown below.

Patient Data

Age: 75
Gender: Female
  1. Type 3 minimally displaced dens fracture of C2 vertebra with fracture line extending through the vertebral body into left foramen transversarium. No other fracture. Alignment is unremarkable.
  2. Grossly enlarged retrosternal goiter measuring up to 65mm in axial diameter displaces and partially compresses the trachea.
  3. There is a probable anterior epidural hematoma from C2 to C4 measuring up to 4mm. Prevertebral soft tissues swelling is likely due to intubation. Right SCM intramuscular hematoma. Right inferolateral cervical subcutaneous fat stranding. Multi-level degenerative change.

Case Discussion

The odontoid process is a portion of the axis which arises from the upper surface of the C2 vertebrae. Fractures of the odontoid process are common and make up almost one fifth of all cervical fractures 2. Odontoid fractures can be classified into three different categories 1.

  • Type I fracture - fracture through tip of dens - 1% of odontoid fractures.
  • Type II fracture - fracture through base of dens - most common odontoid fracture
  • Type III fracture - extension through vertebral body of axis

The grading of the fracture dictates management. Type I fractures can be managed conservatively with a hard collar for 6-8 weeks in duration.

Type II fractures are unstable and non union rates without surgical management is up to 85%. Their tendency for non-union is due to the limited amount of cancellous bone contact area between the peg and the cervical body.

This is in contrast to type II fractures which can be managed conservatively. The amount of cancellous bone contact is greater compared to type II fractures. In our patient, this displaced type III odontoid process fracture was anatomically reduced and then immobilized with a halo vest.

Also note the large, incidental thyroid goiter. It enhances heterogeneously, and displays flecks of calcification within the mass itself. It is likely that this mass was a papillary carcinoma of the thyroid.

Case courtesy of A/Prof. Pramit Phal.

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