title: Spontaneous atlantoaxial rotatory fixation in old age after cerebral infarction: case report.
abstract: METHODS
  Case report of spontaneous Fielding and Hawkins Type I atlantoaxial rotatory fixation in a 78-year-old man after hemiplegia and homonymous hemianopsia caused by cerebral infarction.
  
  
  OBJECTIVE
  To describe a case of spontaneous atlantoaxial rotatory fixation in old age and review previous adult cases of atlantoaxial rotatory fixation without fracture.
  
  
  BACKGROUND
  Atlantoaxial rotatory fixation in adults is a relatively rare finding and is mainly caused by trauma. To the author's knowledge, there has been no previous report of spontaneous atlantoaxial rotatory fixation in old age.
  
  
  METHODS
  The patient's head was fixed in a 40 degrees left-rotated position. Left hemiplegia and homonymous left-side hemianopsia developed due to cerebral infarction. Computed tomography of the cervical spine clearly showed rotatory fixation of the atlas on the axis.
  
  
  RESULTS
  Successful reduction was obtained after 1 day of skull traction.
  
  
  CONCLUSIONS
  It was hypothesized that repeated left-rotational stress due to homonymous hemianopsia loaded to the atlantoaxial joint caused abnormal laxity of the joint.
authors.affiliation: Department of Orthopaedic Surgery, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Japan. kanchi@bell.shiga-med.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Mori
authors.forename: S
authors.initials: S
authors.lastname: Hukuda
authors.forename: A
authors.initials: A
authors.lastname: Katsuura
authors.forename: Y
authors.initials: Y
authors.lastname: Saruhashi
authors.forename: S
authors.initials: S
authors.lastname: Asajima
mesh_terms: D000368:Aged; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000473:pathology*; D002544:Cerebral Infarction / Q000150:complications*; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D016916:Joint Deformities, Acquired / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy; D008297:Male; D011859:Radiography; D012399:Rotation; D014103:Torticollis / Q000150:complications / Q000209:etiology / Q000628:therapy; D014143:Traction; D016896:Treatment Outcome