Odontoid fractures are very common in older adults and are associated with a high mortality rate. The aim of this study was to evaluate the outcomes after conservative treatment of non-displaced odontoid fractures and surgical treatment of displaced fractures in patients older than 70 years. It was hypothesized that early mortality of displaced fractures is higher than in non-displaced fractures.

This was a single-center retrospective observational study of odontoid fractures (type II in the Anderson and Alonzo classification) in patients older than 70 years that occurred between 2014 and 2017. Conservative treatment with immobilization for 3 months was proposed when the fracture was displaced less than 2 mm (non-displaced fracture group). Surgical treatment in the form of anterior screw fixation was proposed when the fracture displacement was more than 2 mm (displaced fracture group). The primary endpoint was the mortality rate at 3 months.

The study included 79 patients (46 women) who had a mean age of 85 years (70–105). The 3-month mortality in the entire cohort was 27% and the 1-year mortality was 30%. Conservative treatment was provided to the 36 patients with non-displaced fractures. The 3-month mortality rate in this group was 11%. A displaced fracture occurred in 43 patients: 17 were treated surgically by anterior screw fixation; 20 could not be operated on because of anesthesia contraindications and 6 died within 24hours of the fracture event. The 3-month mortality rate in this group was 40%; 3 of the 17 operated patients died from postoperative respiratory complications; 8 of the 20 patients with contraindications died, in addition to the 6 that died soon after the fracture occurred.

This study confirms that mortality and morbidity are high following odontoid fractures. The mortality rate was significantly higher in patients with displaced fractures, confirming our hypothesis. The mortality rate was especially high when patients with displaced fractures could not undergo surgery because of anesthesia contraindications. Also, there was a high rate of respiratory complications after anterior screw fixation of displaced fractures.

Given our findings, conservative treatment should be compared to surgical treatment for displaced fractures and the anterior approach should be compared to the posterior one for surgical cases.

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