title: Atlanto-odontoid osteoarthritis. Appearance and prevalence at computed tomography.
abstract: METHODS
  In this prospective study, the authors evaluated the atlanto-odontoid (AO) joint in 500 consecutive patients who underwent computed tomographies (CTs) of the brain or paranasal sinuses.
  
  
  OBJECTIVE
  The objective of the study was to determine age specificity of various morphologic abnormalities related to osteoarthritis at the AO joint in patients referred for CT primarily to exclude brain or sinus abnormalities.
  
  
  BACKGROUND
  In all patients, at least two axial slices through the AO joint were evaluated by two authors, and agreement was reached by consensus.
  
  
  METHODS
  Abnormal morphology was categorized into three groups: (1) osteophytosis; (2) obliteration of the joint space; and (3) transverse ligament calcification.
  
  
  RESULTS
  In a significant percentage of older individuals, some form of degenerative disease is present. These changes show a roughly linear progression with advancing age.
  
  
  CONCLUSIONS
  Morphologic changes related to AO osteoarthritis are frequent coincidental findings in patients referred for CT examination of the brain or paranasal sinuses. Awareness of the appearance and prevalence of degenerative changes in the AO joint on CT is important because reports in the literature and earlier findings of the authors indicate that these changes can be a source of suboccipital headache.
authors.affiliation: Department of Radiology, Leyenburg Hospital, The Hague, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Zapletal
authors.forename: R E
authors.initials: RE
authors.lastname: Hekster
authors.forename: J S
authors.initials: JS
authors.lastname: Straver
authors.forename: J T
authors.initials: JT
authors.lastname: Wilmink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed