The AOSpine North America Geriatric Odontoid Fracture Mortality Study: a retrospective review of mortality outcomes for operative versus nonoperative treatment of 322 patients with long-term follow-up.

STUDY DESIGN: Retrospective, multicenter cohort study. OBJECTIVE: Assess for differences in short- and long-term mortality between operative and nonoperative treatment for elderly patients with type II odontoid fractures. SUMMARY OF BACKGROUND DATA: There is controversy regarding whether operative or nonoperative management is the best treatment for elderly patients with type II odontoid fractures. METHODS: This is a retrospective study of consecutive patients aged 65 years or older with type II odontoid fracture from 3 level I trauma centers from 2003-2009. Demographics, comorbidities, and treatment were abstracted from medical records. Mortality outcomes were obtained from medical records and a public database. Hazard ratios (HRs) and 95% confidence intervals (CI) were calculated. RESULTS: A total of 322 patients were included (mean age, 81.8 yr; range, 65.0-101.5 yr). Compared with patients treated nonoperatively (n = 157), patients treated operatively (n = 165) were slightly younger (80.4 vs. 83.2 yr, P = 0.0014), had a longer hospital (15.0 vs. 7.4 d, P < 0.001) and intensive care unit (1.5 vs. 1.1 d, P = 0.008) stay, and were more likely to receive a feeding tube (18% vs. 5%, P = 0.0003). Operative and nonoperative treatment groups had similar sex distribution (P = 0.94) and Charlson comorbidity index (P = 0.11). Within 30 days of presentation, 14% of patients died, and at maximal follow-up (average = 2.05 yr; range = 0 d-7.02 yr), 44% had died. On multivariate analysis, nonoperative treatment was associated with higher 30-day mortality (HR = 3.00, 95% CI = 1.51-5.94, P = 0.0017), after adjusting for age (HR = 1.10, 95% CI = 1.05-1.14; P < 0.0001), male sex (P = 0.69), and Charlson comorbidity index (P = 0.16). At maximal follow-up, there was a trend toward higher mortality associated with nonoperative treatment (HR = 1.35, 95% CI = 0.97-1.89, P = 0.079), after adjusting for age (HR = 1.07, 95% CI = 1.05-1.10; P < 0.0001), male sex (HR = 1.55, 95% CI = 1.10-2.16; P = 0.012), and Charlson comorbidity index (HR = 1.28, 95% CI = 1.16-1.40; P < 0.0001). CONCLUSION: Surgical treatment of type II odontoid fracture in this elderly population did not negatively impact survival, even after adjusting for age, sex, and comorbidities. The data suggest a significant 30-day survival advantage and a trend toward improved longer-term survival for operatively treated over nonoperatively treated patients. LEVEL OF EVIDENCE: 4.