Surgical vs nonoperative treatment of Hadley type IIA odontoid fractures.

Background: Type II odontoid fractures with additional chip fragments are rare in clinical practice, accounting for < 10% of all odontoid fractures. Hadley et al were the first to describe these fractures as an individual subtype (IIA).
Objective: To analyze the outcome of patients after surgical or nonoperative treatment of Hadley type IIA odontoid fractures.
Methods: We analyzed the records of 46 patients at an average of 64 years of age at the time of injury. Twenty-five patients underwent surgical stabilization by anterior screw fixation and were entered into study group A; 21 patients were treated nonoperatively by halo vest immobilization and included in study group B.
Results: Thirty-seven patients (84%) returned to their preinjury activity level and were satisfied with their treatment. Using the Cervical Spine Outcomes Questionnaire to quantify the clinical outcome, we had an overall outcome score of 21.8. We did not find a significant difference in the overall clinical outcome between study groups. Bony fusion was achieved in 35 patients (80%). We had a nonunion rate of 13% after anterior screw fixation and a significantly higher rate of 30% after halo vest immobilization. Failure of reduction or fixation occurred in 12 patients (27%), with a significantly higher failure rate after halo vest immobilization.
Conclusion: Hadley type IIA odontoid fractures are inherently unstable and impede proper realignment. These fractures have a significantly increased risk for secondary loss of reduction and bony nonunion, particularly after nonoperative management. Early surgery should be considered to avoid further complications.