This classification was proposed by Allen and Ferguson in 19823 and at the time of writing (July 2016) remains the most widely used system for describing subaxial cervical spine injury.
Allen and Ferguson classification is used for research purposes to classify subaxial spine injuries. It is based of the mechanism of injury and position of neck during injury.
The AOSpine subaxial cervical spine injury classification system (using the four main injury types or at the sub-types level) allows a significantly better agreement than the Allen and Ferguson classification of subaxial cervical spine injury. The A&F scheme does not allow reliable communication between medical professionals 1).
Flexion and compression
Flexion and distraction (facet joint dislocation)
Extension and compression
Extension and distraction