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 immobilised with a halo vest.
Also note the large, incidental thyroid goitre. 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.