Fractures of the odontoid process are the most common fractures of the cervical spine in patients over the age of 70 years. The incidence of fracture nonunion in this population has been estimated to be 20-fold greater than that in patients under the age of 50 years if surgical stabilization is not used. Anterior and posterior approaches have both been advocated, with excellent results reported, but surgeons should understand the drawbacks of the various techniques before employing them in clinical practice.
A retrospective review was undertaken to identify patients who had direct fixation of an odontoid fracture at a single institution from 1991 to 2006. Patients were followed up using flexion-extension radiographs, and stability was evaluated as bone union, fibrous union, or nonunion. Patients with bone or fibrous union were classified as stable. In addition, the incidence of procedure- and nonprocedure-related complications was extracted from the medical record.
Of the 57 patients over age 70 who underwent placement of an odontoid screw, 42 underwent follow-up from 3 to 62 months (mean 15 months). Stability was confirmed in 81% of these patients. In patients with fixation using 2 screws, 96% demonstrated stability on radiographs at final follow-up. Only 56% of patients with fixation using a single screw demonstrated stability on radiographs. In the immediate postoperative period, 25% of patients required a feeding tube and 19% had aspiration pneumonia that required antibiotic treatment.
Direct fixation of Type II odontoid fractures showed stability rates > 80% in this challenging population. Significantly higher stabilization rates were achieved when 2 screws were placed. The anterior approach was associated with a relatively high dysphagia rate, and patients must be counseled about this risk before surgery.
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