Matched case-control study of odontoid osteosynthesis vs hard collar immobilisation for Type II odontoid fractures in the elderly: higher risk of adverse events with no long-term functional benefits

Abstract OBJECTIVE Odontoid fractures in the elderly carry high morbidity and mortality, yet optimal management remains controversial. This study compares functional and radiological outcomes between anterior odontoid screw fixation (AOSF) and hard collar immobilisation in elderly patients with acute odontoid fractures. METHODS Single-centre matched case-control study of AOSF versus hard collar immobilisation in patients ≥ 65 years. Patients were matched using clinical outcome predictors (age; frailty; co-morbidities; fracture morphology). Included patients were deemed by the lead surgeon and multidisciplinary team to have sufficient clinical equipoise between operative and non-operative management. Outcomes were collected retrospectively (complications, mortality, union rates, screw positioning) and prospectively using patient-reported outcome measures (Visual Analogue Scale [VAS]; Neck Disability Index [NDI]; EQ-5D-5L; Dysphagia Outcome and Severity Scale [DOSS]). RESULTS Of 381 acute odontoid fractures, 70 met the inclusion criteria (35 AOSF; 35 matched Hard Collar). The operative group had longer hospitalisation (21 ± 23.69 vs 11 ± 7.52 days; p = .042) and higher incidence of adverse events per patient (2.17 vs 0.91, p < .001). Dysphagia occurred in 46% of operative cases. Seven screw-related complications occurred, with one revision. Three treatment-related deaths occurred in the operative group; none in the conservative. Functional outcomes were similar between groups; however, neck pain (VAS) was lower following AOSF (2.00 ± 2.02 vs 4.69 ± 3.95; p = .008). Non-union rates were comparable. CONCLUSIONS Odontoid osteosynthesis was associated with longer hospitalisation, treatment-related morbidity and mortality, while demonstrating a marginal improvement in neck pain. Larger randomised control studies are needed to determine the role of AOSF in this population.