title: Osteoporosis Is the Most Important Risk Factor for Odontoid Fractures in the Elderly.
abstract: 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. We conducted a retrospective analysis of 5303 patients (aged ≥60 years) admitted to a level I trauma center between January 2008 and January 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. In all groups, the severity of degenerative changes of the C-spine increased with age (all p < 0.05) and was inversely correlated with cBMD (all p < 0.05). cBMD was the only significant predictor of a TOF in a multivariate logistic regression model (adjusted odds ratio [OR] = 3.066, 95% confidence interval [CI] 1.432-6.563 for cervical osteoporosis). An association between odontoid cysts and TOF reached significance only in Anderson and D'Alonzo (A&D) type II TOFs (aOR = 1.383; 95% CI 1.012-1.890). Patients with OCSFs, compared with patients with TOFs, were younger (median 74 versus 83 years) and had a higher cBMD (median 208 mg/mL versus 172 mg/mL). No differences were observable when comparing cBMD and grades of degenerative changes between OCSFs and their control group (all p >0.1). 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. © 2017 American Society for Bone and Mineral Research.
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Johannes
authors.identifier: http://orcid.org/0000-0002-9177-2289
authors.initials: J
authors.lastname: Kaesmacher
authors.affiliation: Department of Neurorsurgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Schweizer
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Valentinitsch
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Baum
authors.affiliation: Department of Neurorsurgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.|Department of Orthopedics, Medizinische Universität Wien, Vienna, Austria.
authors.forename: Anna
authors.initials: A
authors.lastname: Rienmüller
authors.affiliation: Department of Neurorsurgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Jan S
authors.initials: JS
authors.lastname: Kirschke
authors.affiliation: Department of Neurorsurgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Ryang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019838:Neck Injuries / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism; D014057:Tomography, X-Ray Computed
keywords: DEGENERATIVE CHANGES; ONDONTOID FRACTURE; OSTEOPOROSIS; SPINE