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The combination of movement, location, and anatomy of the axis predisposes it to multiple and varied fracture/dislocations distinct from other vertebrae. We examine all forms of axis fractures and address the appropriate treatment for each specific fracture type. In a retrospective review of 625 cervical spine fractures during an 8-year period, we found 107 axis fractures. There were 25 hangman's fractures (23%), 59 odontoid fractures (55%), and 23 miscellaneous fractures (22%). Each case was characterized by age, sex, the presence of associated injuries, presenting symptoms and findings, initial treatment, and results of that treatment. Excluding 6 early deaths, 90 of 101 patients were located for a median follow-up of 3.2 years. We found that 17% of cervical fractures involve the axis. Axis fractures have a high association with head and other cervical spine injuries, 40% and 18%, respectively. Few neurological deficits result from a fracture of the 2nd cervical vertebra. Hangman's fractures are effectively treated with external stabilization, preferably with a halo vest. We noted a shorter period of treatment using the halo vest as compared to the SOMI brace. Nonunion occurred in 26% of odontoid Type II fractures, but occurred in 67% of those with dens displacement of 6 mm or greater, regardless of age or direction of dislocation. We recommend early surgical therapy for this subgroup. There is no correlation between age and the rate of nonunion. In patients with odontoid Type II fractures with dens displacement of 0 to 5 mm, fusion occurs with external stabilization alone. Odontoid Type III fractures are one-half as common as Type II fractures, and all heal well with external stabilization. Twenty-two per cent of acute axis fractures are not hangman's or odontoid fractures. Miscellaneous fractures of the axis generally do well with external stabilization and immobilization.
Hadley et al. (Thu,) studied this question.