title: Os odontoideum: chronic neck pain after car accident; failure of two posterior atlantoaxial arthrodeses--medicolegal issues in the occupational setting.
abstract: OBJECTIVE
  To present the case of a woman with previously asymptomatic os odontoideum (OO) who developed chronic neck pain after a car accident.
  
  
  METHODS
  A 32-yr-old woman developed slight constant neck pain following a car accident. Radiographs revealed OO with 12-mm atlantoaxial subluxation on neck flexion. There was no spinal cord compression clinically or on magnetic resonance imaging.
  
  
  RESULTS
  Posterior atlantoaxial arthrodesis was performed twice but the bone graft resorbed for no apparent reason. The patient was treated with analgesics, physiotherapy and a Philadelphia collar to prevent accidental spinal cord compression.
  
  
  CONCLUSIONS
  OO patients may remain asymptomatic if "space available for cord" is sufficient. Even low velocity rotational injury can precipitate chronic neck pain in adults with OO. Posterior atlantoaxial arthrodesis can fail inexplicably even under the best circumstances. Medicolegal issues in the occupational setting are discussed.
authors.affiliation: Bristol Edinger Medical Clinic, Santa Ana, CA 92704.
authors.forename: G S
authors.initials: GS
authors.lastname: Lohiya
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007603:Jurisprudence; D009333:Neck / Q000503:physiopathology; D019838:Neck Injuries; D009809:Odontoid Process / Q000293:injuries*; D010146:Pain; D011859:Radiography; D013123:Spinal Fusion