BACKGROUND AND OBJECTIVES: Managing acute type II odontoid fractures in the elderly is challenging because of comorbidities and frailty. This study evaluates radiological and functional outcomes of conservative vs surgical treatment. METHODS: A retrospective analysis at a single US institution on elderly patients with acute type II odontoid fractures (January 2015-December 2023) was performed. Bivariate and logistic regression analyses compared outcomes and identified predictors of union. RESULTS: The study included 273 patients, 20 of which expired during hospital admission, leaving 253 patients available for analysis with outcomes data. The median age was 82 years (IQR: 74-90), and 53% were female. Of 253 patients, 235 (93%) received conservative treatment and 18 (7%) underwent surgical fixation. At a median radiological follow-up of 3.75 months, surgical patients had higher fracture union rates (44% vs 10%, P <
.01). Modified Rankin Scale ≤2 rates were similar (75% vs 73%, P = .85), but conservative treatment showed higher excellent pain control (75% vs 47%, P <
.01). Logistic regression showed high union prediction accuracy (area under the curve = 0.93). Surgical fixation was the strongest predictor of union (adjusted odds ratio [aOR] = 6.6, 95% CI 1.8-24.5). Age ≥80 years (aOR = 0.1, 95% CI 0.05-0.2), smoking history (aOR = 0.2, 95% CI 0.1-0.6), osteoporosis (aOR = 0.1, 95% CI 0.02-0.6), and mild (aOR = 0.12, 95% CI 0.06-0.3), moderate (aOR = 0.08, 95% CI 0.03-0.2), and severe frailty (aOR = 0.04, 95% CI 0.01-0.1) were negatively associated with union. Angulation ≥11° also reduced union odds (aOR = 0.16, 95% CI 0.07-0.4). CONCLUSION: Surgical fixation positively predicts fracture union, whereas advanced age, smoking, osteoporosis, frailty, and angulation (≥11°) reduce union odds. Surgery may enhance union odds, but conservative management remains effective with better pain control, without compromising long-term functional outcomes.