339 - Evaluation and Treatment of C2 (Axis) Fractures and Instability

Abstract

C2 fractures are common cervical fractures, with odontoid fractures representing the most common type of axis fracture. It is imperative to understand the anatomy of the axis to help determine the mechanism of injury and treatment of various axis fractures. Odontoid fractures are classified into type I, II, and III with additional subtypes. This classification helps determine the appropriate treatment. Type I fractures involve the tip of the odontoid and are typically treated with external immobilization. Type II fractures go through the base of the dens and are treated with external immobilization or surgery depending on certain characteristics including displacement, angulation, and neurological status. Surgical treatments include anterior and posterior approaches. Type III fractures go through the body of C2, and most are treated adequately with external immobilization. There are many surgical techniques for treatment of axis fractures. An anterior odontoid screw can be placed for acute and well-aligned odontoid fractures. Multiple posterior techniques are available including the transarticular screw (Magerl technique), posterior C1–2 screw-rod fixation (Harms technique), and wire and cable techniques. Hangman’s fracture, or traumatic spondylolisthesis of the axis, is the second most common axis fracture. Most hangman’s fractures are not associated with neurological injury and are managed nonsurgically. If surgery is required, anterior cervical discectomy and fusion at C2–3 is a viable option.