Low-Threshold-For-Surgery Versus Primarily-Conservative Treatment for Odontoid Fractures in the Elderly: Evaluating Practice Variation in The Netherlands

Study Design: Retrospective cohort study. Objectives: Odontoid fractures are the most common cervical spine fractures in the elderly. The optimal treatment remains controversial. The aim of this study was to compare results of a low-threshold-for-surgery strategy (surgery for dislocated fractures in relatively healthy patients) to a primarily-conservative strategy (for all patients). Methods: Patient records from 5 medical centers were reviewed for patients who met the selection criteria (e.g. age ≥55 years, type II/III odontoid fractures). Demographics, fracture types/characteristics, fracture union/stability, clinical outcome and mortality were compared. The influence of age on outcome was studied (≥55-80 vs ≥80 years). Results: A total of 173 patients were included: 120 treated with low-threshold-for-surgery (of which 22 primarily operated, and 23 secondarily) vs 53 treated primarily-conservative. No differences in demographics and fracture characteristics between the groups were identified. Fracture union (53% vs 43%) and fracture stability (90% vs 85%) at last follow-up did not differ between groups. The majority of patients (56%) achieved clinical improvement compared to baseline. Analysis of differences in clinical outcome between groups was infeasible due to data limitations. In both strategies, patients ≥80 years achieved worse union (64% vs 30%), worse stability (97% vs 77%), and – as to be expected – increased mortality <104 weeks (2% vs 22%). Conclusions: Union and stability rates did not differ between the treatment strategies. Advanced age (≥80 years) negatively influenced both radiological outcome and mortality. No cases of secondary neurological deficits were identified, suggesting that concerns for the consequences of under-treatment may be unjustified.