title: Suspected atlantoaxial rotatory fixation-subluxation: the value of multidetector computed tomography scanning under general anesthesia.
abstract: METHODS
  Clinical case reports and radiologic study.
  
  
  OBJECTIVE
  To emphasize the value of computed tomography (CT) scan under general anesthesia in order to prevent misdiagnosing atlantoaxial rotatory fixation-subluxation in children with acute torticollis.
  
  
  BACKGROUND
  A "cock-robin" posture clinically characterizes painful rotatory fixation of the atlantoaxial joint in children. Classically, the observation of persistent displacement of the dens between the lateral mass of the atlas and asymmetry of the atlantoaxial joint on radiography confirmed the diagnosis. More recently, (dynamic) CT scanning or magnetic resonance imaging is used to confirm the diagnosis. However, when a CT scan is performed with the head of the patient in the "cock-robin" position, there is a serious chance of misinterpretation due to the abnormal anatomic position of the atlantoaxial joint.
  
  
  METHODS
  Four consecutive cases of children presenting with an acute torticollis were analyzed. All were neurologically intact. A conventional single-slice CT scan made with the head rotated in the "cock-robin" position confined rotatory dislocation of the atlantoaxial joint. Subsequently, the patients were referred to our hospital for further treatment. To confirm the diagnosis before potential treatment, a multidetector CT scan under general anesthesia was performed in all 4.
  
  
  RESULTS
  The multidetector CT scans under general anesthesia did not show any abnormalities. All patients were treated conservatively and recovered completely within 4 weeks of being referred to our hospital.
  
  
  CONCLUSIONS
  Multidetector CT scanning under general anesthesia is recommended in children when there is suspicion for a spontaneously developed atlantoaxial rotatory fixation-subluxation.
authors.affiliation: Department of Orthopedic Surgery, Academic Medical Center, Amsterdam, The Netherlands. h.d.been@amc.uva.nl
authors.forename: Henk D
authors.initials: HD
authors.lastname: Been
authors.forename: Gino M M J
authors.initials: GM
authors.lastname: Kerkhoffs
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
mesh_terms: D000768:Anesthesia, General; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging*; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007103:Immobilization; D004204:Joint Dislocations / Q000000981:diagnostic imaging*; D008297:Male; D017410:Practice Guidelines as Topic; D011857:Radiographic Image Interpretation, Computer-Assisted; D016059:Range of Motion, Articular; D012399:Rotation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014103:Torticollis / Q000000981:diagnostic imaging*