Classification Anderson & D'alonzo

Type 1

Tip avulsion

- alar ligament avulsion

- fracture off one side of tip of dens

Management

- associated with atlantoaxial instability

- manage in collar

Type 2

Fracture of base of dens

Epidemiology

Neck involved in 86%

- second most common site after hands and feet

- closely associated with MCPJ subluxation

Associations

Males / Steroid use / Seropositivity Nodules / Severe long standing disease

Conditions

Atlanto-axial subluxation

Subaxial subluxation

Superior migration ondontoid