title: Mobile and reducible atlantoaxial dislocation in presence of occipitalized atlas: report on treatment of eight cases by direct lateral mass plate and screw fixation.
abstract: METHODS
  This is a retrospective review on the application of the authors' technique of atlantoaxial lateral mass plate and screw fixation on a rare subset of patients having mobile and reducible atlantoaxial subluxation in the presence of occipitalized atlas.
  
  
  OBJECTIVE
  Mobile and reducible atlantoaxial dislocation in the presence of an occipitalized atlas is extremely rare. We retrospectively analyzed the management of eight such patients who were treated by lateral mass plate and screw fixation.
  
  
  BACKGROUND
  The authors report their experience with a rare congenital craniovertebral anomaly where there was a mobile and reducible atlantoaxial dislocation in the presence of the occipitalized atlas. The cases were treated by lateral mass plate and screw method of treatment described by the authors in 1994.
  
  
  METHODS
  Eight patients with occipitalized atlas had a mobile and completely reducible atlantoaxial dislocation. These patients were treated between the years 1996 to 2003 and underwent a direct atlantoaxial lateral mass fixation. The follow-up ranges from 4 months to 6 years (average, 48 months).
  
  
  RESULTS
  All patients underwent a successful fixation and ultimately achieved a solid bony fusion. There were no intraoperative or postoperative complications.
  
  
  CONCLUSIONS
  Although lateral mass plate and screw fixation in the presence of occipitalized atlas is technically a relatively difficult and anatomically a precise surgical procedure, the firm and segmental stabilization that it provides offers an optimum situation for bony fusion.
authors.affiliation: Department of Neurosurgery, K.E.M. Hospital and Seth G. S. Medical College, Mumbai, India. atulgoel62@hotmail.com
authors.forename: Atul
authors.initials: A
authors.lastname: Goel
authors.forename: Arvind G
authors.initials: AG
authors.lastname: Kulkarni
mesh_terms: D000293:Adolescent; D000328:Adult; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001860:Bone Plates; D001863:Bone Screws; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000601:surgery*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009777:Occipital Bone / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D012189:Retrospective Studies