Perioperative Complications and Mortality Following Anterior Odontoid Screw Fixation in Elderly Patients: A National Database Analysis

Objective

To identify predictors of short-term mortality and complications after anterior odontoid screw fixation.

Methods

This was a retrospective analysis of a national database. The American College of Surgeons National Quality Improvement Database was queried using Current Procedural Terminology codes to identify patients aged ≥60 years who underwent surgery for anterior fixation of odontoid fracture admitted from 2007 to 2016. Univariate analysis and subsequent multivariate analysis were used to analyze risk factors for postoperative complications and 30-day postoperative mortality. Complications were defined as surgical-site infection, wound breakdown, pneumonia, venous thromboembolism, stroke, myocardial infarction, sepsis, renal progressive renal insufficiency/acute kidney injury, or cardiac arrest.

Results

A total of 198 patients were identified. Mean age was 77.7 (±8.7) years and 60.6% were female. Overall mortality rate was 7.6%, and the complication rate was 9.1%. In multivariate analysis, dependent functional status (0.012; odds ratio [OR] 5.2; 95% confidence interval [CI] 1.42–18.72) and preoperative systemic inflammatory response syndrome (P = 0.011; OR 6.2; 95% CI 1.52–25.79) predicted mortality. Emergency case status (P = 0.033; OR 3.4; 95% CI 1.10–10.70) predicted perioperative complications. Age was not significantly associated with either complications or mortality in multivariate analysis.

Conclusions

Functional dependence and preoperative systemic inflammatory response syndrome predict mortality following odontoid screw placement. Although age often is considered a limiting factor in pursuing surgical intervention in patients with odontoid fracture, age did not independently increase odds of either complications or perioperative mortality in this analysis. Further studies are needed to explore these findings.

Introduction

The number of elderly Americans is projected to increase markedly over the next several decades, with more than one fifth of the population expected to be older 60 years of age by 2050.¹ With this, clinicians can expect to encounter conditions that are more prevalent in this age group, including odontoid fractures²—the most common cervical fracture in patients aged older than 70 years.³ The Anderson−D'Alonzo classification categorizes these fractures into 3 types.⁴ Generally, Type I and Type III fractures are treated nonoperatively, but Type II fractures often require surgery in the presence of neurologic compromise, high risk of nonunion, excessive angulation, or ligamentous injury.2, 5, 6

Although there are circumstances that require posterior fixation, anterior odontoid screw fixation confers several advantages, such as maintenance of atlantoaxial rotation, shorter operative times, and reduced bleeding risk.7, 8 Current guidelines from the American Association of Neurological Surgeons and Congress of Neurological Surgeons suggest that surgical management of odontoid fracture is appropriate for patients aged older than 50 years (Level II recommendation) using either an anterior or posterior approach (Level III recommendation).2, 9 Several studies examined in small cohorts postoperative complications and mortality in patients treated with anterior odontoid screw fixation; however, there is limited literature describing risk factors.10, 11, 12, 13 With perioperative mortality ranging from 7% to 9%, the aim of this study was to identify risk factors for postoperative complications and mortality in patients older than 60 years undergoing anterior odontoid screw fixation.11, 12, 13