spine
Fracture types of axis, C2 by Effendi, modified by Levine & Edwards
The classification of fractures of axis was introduced by Effendi et al. and later modified by Lewine and Edwards. With further two types added (IA and IIA), the modified classification has five types.
| Type | Description |
|---|---|
| Type I | fracture of the pedicles, intervertebral disc C2/3 is intact, dislocation ≤3mm without angulation |
| Type IA | fracture lines on each side are not parallel, fracture line may involve foramen transversarium on one side |
Anderson and D'Alonzo classification of odontoid fractures, fractures of dens axis (C2)
Odontoid fractures are classified into three types. Type III is not an odontoid fracture but rather fracture of the vertebral body.
| Type | Description |
|---|---|
| Type I | avulsion fracture of the tip of dens (rare) |
| Type II | fracture at the base of dens - most common (cca 2/3) |
| Type III | fracture extends into the body of the vertebra, does not involve dens (cca 1/3) |
Fracture of atlas (C1) - Gehweiler classification
The Gehweiler classification divides fractures of the first cervical vertebra into five types. Type III is also refered to as Jefferson fracture. The classical Jefferson fracture is a four part fracture, where both the anterior and the posterior arch is fractured twice, but fractures with two or three fracture parts may also occur.
| Type | Description |
|---|---|
| Type I | fracture of the anterior arch |
| Type II | fracture of the posterior arch |
Fielding classification of atlanto-axial rotatory fixation
In 1977, Fielding and Hawkings divided atlantoaxial roratory subluxation into the following four types.
| Type | Description | Ligaments |
|---|---|---|
| Type I | Simple rotatory displacement (rotatory fixation) without anterior shift. | The transverse ligament is intact and the dens acts as pivot |
| Type II | Rotatory fixation with anterior diplacement between 3 and 5mm. |
