Osteoporosis Is the Most Important Risk Factor for Odontoid Fractures in the Elderly

Background Traumatic odontoid fractures (TOFs) have been described as the most common injury affecting the C-spine in the elderly. Previous studies have identified degenerative changes and bone loss as important predisposing factors. However, their interaction and respective age-adjusted impact needs further clarification. Methods Retrospective analysis of 5303 patients (≥60 years) admitted to a level-I trauma center between 01/2008-01/2016 who underwent CT imaging of the C-spine. Ninety-two patients with TOF and 80 patients with other cervical spine fractures (OCSF) were identified and a respective 3:1 age- and sex-matched control group without fractures after trauma was built. In all groups, cervical bone mineral density (cBMD) was determined using phantom calibration and degenerative changes were evaluated in a qualitative manner. Results In all groups, the severity of degenerative changes of the C-spine increased with age (all p  0.1). Conclusions Decreased cBMD is the major predisposing factor for the occurrence of TOF, but not for OCSF in the elderly. The severity of odontoid cysts was found to be a cBMD-independent factor associated with A&D type II TOFs. However, degenerative changes in the odontoid neighboring joints seem to be an epiphenomenon of bone loss and older age, but do not independently predispose for TOF. Level of Evidence Level III-case-control study. This article is protected by copyright. All rights reserved