Carol M. Browner

Axis fractures: a comprehensive review of management and treatment in 107 cases

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 hangmans 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. Hangmans 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 hangmans or odontoid fractures. Miscellaneous fractures of the axis generally do well with external stabilization and immobilization.

Facet fracture-dislocation injuries of the cervical spine.

Sixty-eight patients with acute traumatic cervical facet fracture-dislocation injuries are presented. These patients represented 6.7% of all cervical spine fractures identified over a 12-year period. Thirty-one patients had unilateral facet injuries and 37 had bilateral facet injuries. Neurological morbidity was 90% and was most severe among bilateral facet injury patients (84% complete injuries). Spinal shock was identified in 13 patients and was a poor prognostic indicator for the subsequent recovery of associated neurological deficits. Closed reduction was attempted in 66 of 68 patients and was successful in 58% of the patients. Seven patients deteriorated. Open reduction-internal fixation was successful in 83% of 24 patients with a 4% morbidity. Seventy-eight percent of patients improved with rapid closed reduction, and 60% improved with open reduction-internal fixation; however, only 10 patients of the entire 68 made significant neurological recoveries. In these 10 patients, the timing of decompression-realignment appeared to be more important than the means of reduction.

New subtype of acute odontoid fractures (type IIA).

A new subtype of axis fracture, thought to be a variant of the Type II odontoid fracture, is described. High resolution, thin section computed tomography can assist in the identification of comminuted fractures at the base of the dens with associated free fracture fragments. Because these injuries are markedly unstable and cannot be suitably realigned and reduced by external means, early surgical therapy should be considered.

Acute traumatic atlas fractures: management and long term outcome.

Fractures of the 1st cervical vertebra (C1) represent 7% of all acute cervical spine fractures. Isolated atlas fractures are most commonly bilateral or multiple fractures through the ring of C1. Frequently (44% of cases), the atlas will be fractured in combination with the axis. Treatment of isolated C1 fractures should be governed by the rules of Spence. The treatment of combination C1-C2 fractures is dictated by the type and severity of the C2 fracture. Experience with 57 cases of acute atlas fractures is reviewed. Nonoperative external immobilization was used in 53 patients (with 1 failure), and early surgical wiring and fusion were performed in 4 patients. The long term outcome from an atlas fracture is good (median follow-up, 40 months).

Axis fractures resulting from motor vehicle accidents. The need for occupant restraints

A total of 625 patients who sustained acute cervical spine fractures were evaluated by the Spinal Cord Injury Service at Barrow Neurological Institute, Phoenix, Arizona, between January 1976 and January 1984. Of them, 107 had fractures of the second cervical vertebra. In a retrospective review, motor vehicle accidents were found to be the most common mechanism of injury, resulting in 73 (68%) of the 107 axis fractures. All axis fracture types were encountered in this subgroup: hangmans (27%), Odontoid Type II (39%), Odontoid Type III (15%), and miscellaneous fractures (19%). Only one of the 30 patients with complete medical records and detailed information about the accident was wearing a seat belt. Equally remarkable is that 15 of the 30 accidents were single car mishaps, where occupant restraints might theoretically provide the most protection. Sixteen of the 30 patients were thrown from their vehicles, another five were found in the backseat, which leads to the conclusion that a significant portion of the driving population does not wear seat belts or shoulder restraints. Patients with axis fractures from an automobile accident had a high rate of associated severe head injuries or other cervical spine fractures, three times that of patients with C–2 fractures from other causes. Motorists who are thrown from their vehicles suffer the most severe trauma and have the highest rates of morbidity and mortality. As many as 25% to 40% of individuals who sustain high cervical fractures in motor vehicle accidents die as a result of their injuries.

Atlas Fractures: Treatment and Long-term Results

Fractures of the first cervical vertebra (C1) represent approximately 7% of all acute cervical spine fractures. Frequently, the atlas will be fractured in combination with the axis (44% of cases). Treatment of isolated C1 fractures should be governed by the rules of Spence. The treatment of combination C1-C2 fractures is dictated by the type and severity of the C2 fracture. Experience with 57 cases of acute traumatic atlas fractures are reviewed. The long-term outcome from an atlas fracture is good (median follow-up, 40 months).