Management and long-term outcome of type II acute odontoid fractures: a population-based consecutive series of 282 patients.

Background Context: The surgical fixation rate of type II odontoid fracture (OFx) in the elderly (≥65 years) is much lower than expected if the treatment adheres to current general treatment recommendations. Outcome data after conservative treatment for elderly patients with these fractures are sparse.

Purpose: The main aim of this study was to determine the long-term outcome after conservative and surgical treatments of type II OFx (all age-groups) to evaluate whether nonoperative treatment yields an acceptable outcome.

Study Design/setting: Retrospective study based on a prospective database.

Patient Sample: Two hundred eighty-two consecutive patients with type II OFx treated at Oslo University Hospital over an 8-year period.

Outcome Measures: Long-term rates of bony fusion, fibrous union, pseudarthrosis, crossover from primary conservative treatment to surgical fixation, new-onset spinal cord injury (SCI), and neck pain were the outcome measures used.

Methods: The present study was based on data extracted from our quality control database for acute cervical spine fractures. All ages were included. In addition, long-term follow-up of alive patients was performed during the years 2018-2019. The follow-up included neurological examination, radiological examination, and scoring of bony fusion status, crossover from primary conservative treatment to surgical fixation, new-onset SCI, neck pain, and Neck Disability Index (NDI score). Data are described by counts, percentages, medians, means, ranges and standard deviations where appropriate. For statistical analyses the Mann-Whitney U test, Wilcoxon signed-rank test, and t tests were used.

Results: During the eight-year study period, we registered 282 consecutive patients with type II OFx; 54% were males, patient age ranged from 15 to 101 years, 84% were ≥65 years of age (WHO definition of elderly), and 51% were ≥80 years of age. Severe comorbidities (American Society of Anesthesiologists, ASA ≥3) were seen in 67%, whereas nonindependent living was registered in 32%. Severe comorbidities and nonindependent living were significantly associated with increasing age (p<.001). SCI secondary to the OFx was seen in 5.3%. Primary treatment of the OFx was conservative (external immobilization alone) in 193 patients (68.4%), open surgical fixation in 87 patients (30.9%), and no treatment in two critically injured patients. At the time of long-term follow-up, 125 patients had died, nine patients declined the invitation to follow-up, and five patients did not respond. Thus, 143 patients were available for follow-up with a median follow-up time of 39 months (range 5-115 months). At long-term follow-up, the fusion status was bony fusion in 39.2% of patients, fibrous union in 57.3%, and pseudarthrosis in 3.5%. The proportion of bony fusion was significantly higher in the primary surgical fixation group (p=.005). No patients had new-onset SCI presenting after the start of primary treatment. The proportion of crossover from primary external immobilization to surgery was 14.4%, whereas proportion of revision surgery in the primary surgical group was 9.5%. There was no significant difference between the primary surgical fixation group and the primary conservative treatment group at long-term follow-up with respect to the proportion of pseudarthrosis and degree of neck pain.

Conclusions: Primary conservative treatment of elderly patients with type II OFx appears to be safe and should be regarded a viable treatment option.