Cervical spine trauma: the common combined conditions.

The two most common groups of combined traumatic conditions of the cervical spine are hyperextension and hyperflexion fracture-dislocations. In a series of 400 patients with fractures and/or dislocations of the cervical spine, 25% had hyperextension and 19% hyperflexion fracture-dislocations. A computer analysis of the cases revealed that there are five distinct types of hyperextension and four types of hyperflexion fracture-dislocations. Each of the types is considered as to incidence, causes, mechanism of injury, and roentgen and differential diagnosis.