Survival analysis of elderly patients with a fracture of the odontoid peg

Fractures of the odontoid peg are common spinal injuries in the elderly. This study compares the survivorship of a cohort of elderly patients with an isolated fracture of the odontoid peg versus that of patients who have sustained a fracture of the hip or wrist. A six-year retrospective analysis was performed on all patients aged > 65 years who were admitted to our spinal unit with an isolated fracture of the odontoid peg. A Kaplan-Meier table was used to analyse survivorship from the date of fracture, which was compared with the survivorship of similar age-matched cohorts of 702 consecutive patients with a fracture of the hip and 221 consecutive patients with a fracture of the wrist. A total of 32 patients with an isolated odontoid fracture were identified. The rate of mortality was 37.5% (n = 12) at one year. The period of greatest mortality was within the first 12 weeks. Time made a lesser contribution from then to one year, and there was no impact of time on the rate of mortality thereafter. The rate of mortality at one year was 41.2% for male patients (7 of 17) compared with 33.3% for females (5 of 15). The rate of mortality at one year was 32% (225 of 702) for patients with a fracture of the hip and 4% (9 of 221) for those with a fracture of the wrist. There was no statistically significant difference in the rate of mortality following a hip fracture and an odontoid peg fracture (p = 0.95). However, the survivorship of the wrist fracture group was much better than that of the odontoid peg fracture group (p < 0.001). Thus, a fracture of the odontoid peg in the elderly is not a benign injury and is associated with a high rate of mortality, especially in the first three months after the injury.