Objective: Despite various reports in the literature, the appropriate treatment of Type II odontoid fractures remains controversial. Although there is an increasing tendency toward surgical treatment of these fractures in recent years, nonoperative treatment strategies are still regarded as a practicable method, particularly in elderly patients with significant comorbidities. One purpose of this study was to determine the functional and radiographic long-term results after rigid immobilization of Type II odontoid fractures using a halothoracic vest. The second aim was to present a case-control series of patients with nonunion of Type II odontoid fractures compared with patients with successful fracture healing to determine specific risk factors for failure of halo immobilization.
Methods: We reviewed the clinical and radiographic records of 90 patients with an average age of 69 years at the time of injury who had undergone nonoperative treatment of odontoid fractures using a halothoracic vest between 1988 and 2004. To identify potential risk factors for failure of halo fixation, patients were divided into "cases" and "controls." Cases were defined as patients with nonfusion after halo immobilization, and controls were patients with successful fracture healing attained with this treatment option.
Results: Seventy-five patients returned to their preinjury activity level and were satisfied with their treatment. The Smiley-Webster scale showed an overall functional outcome score of 1.64. Successful fracture healing was achieved in 76 patients (84%). In 14 patients, nonunion was diagnosed by standard x-rays and additional computed tomographic scans within 6 to 12 months after trauma. Referring to possible risk factors for failure of halo fixation, nonunion was found significantly more often in older patients and in those with displaced fractures of the odontoid. Secondary loss of reduction and delay of treatment were identified as further risk factors for nonfusion.
Conclusion: With regard to successful fracture healing and functional results of the patients, we had a satisfactory outcome after halo fixation of Type II odontoid fractures. Although a fusion rate of 84% should not be deemed as optimal, nonoperative management of these fractures using a halothoracic vest seems to be an appropriate treatment strategy in patients who are not suitable for surgical treatment.