P150. Differences in survivorship between elderly patients with odontoid and hip fractures: a retrospective cohort study

Abstract

<h3>BACKGROUND CONTEXT</h3> Both odontoid fractures and hip fractures often occur from a standing height and are thus categorized as fragility fractures. Studies have reported a 1-year mortality rate of 37.5% for patients with odontoid fractures in comparison to a 1-year mortality rate of 32% for those with hip fractures within the same age-matched cohort. However, an evaluation of comorbidities' influence on the relative mortality of hip and odontoid fractures is lacking. <h3>PURPOSE</h3> The purpose of this study is to compare the mortality and risk factors of isolated odontoid fractures to those with isolated hip fractures among the elderly population (>65 years). <h3>STUDY DESIGN/SETTING</h3> A single institution 14-year retrospective review of a level 1 trauma center with six fellowship trained spine surgeons. <h3>PATIENT SAMPLE</h3> This study included elderly patients (>65 years at the time of injury) who sustained either an isolated hip fracture or isolated odontoid fracture. <h3>OUTCOME MEASURES</h3> Primary outcomes were age at time of injury, comorbidities (Charlson Comorbidity Index (CCI)) and time from injury to mortality. <h3>METHODS</h3> Patients greater than 65 years with an isolated odontoid fracture or hip fracture from 2006 to 2020 were identified. Data collected include demographic information, time from injury to death, and living status. Death was assessed using a national social security database. Patients were matched on a 4:1 basis on both age and CCI. A Kaplan-Meier table was used to analyze survivorship from the date of fracture between age- and CCI score-matched patients with an odontoid fracture or hip fracture. A Cox regression analysis was used to assess the effect of age and CCI score on survival. <h3>RESULTS</h3> A total of 1,234 patients with isolated hip fractures and 133 patients with isolated odontoid fractures were identified. After matching, a total of 532 hip fracture patients and 133 odontoid fracture patients were included in the analysis. A Kaplan-Meier estimate analysis revealed that survivorship for elderly patients with isolated odontoid fractures was longer compared to elderly patients with isolated hip fractures (p<0.0001). Furthermore, patients with isolated hip fractures experienced an increased risk of death compared to patients with isolated odontoid fractures (hazard ratio [HR] = 1.47, p = 0.03), regardless of CCI score. Although risk of death was greater following hip fractures, CCI scores were independently associated with an increased risk of death in both patient groups (HR = 1.43, p = 0.004). <h3>CONCLUSIONS</h3> Survivorship following isolated hip or odontoid fractures decreases substantially over time. Elderly patients who suffer isolated odontoid fractures have a lower risk of death compared to elderly patients who suffer isolated hip fractures. The presence of comorbidities significantly increases the risk of death in patients with isolated hip or odontoid fractures. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.