title: Atlantoaxial fusion and retrodental pannus in rheumatoid arthritis.
abstract: METHODS
  This study analyzed the influence of atlantoaxial fusion in rheumatoid arthritis patients on inflammatory retrodental pannus.
  
  
  OBJECTIVE
  To determine the value of fusion on the magnitude of pannus as a compressive structure on the spinal cord.
  
  
  BACKGROUND
  Transverse and vertical instability may lead to neurologic deficits from spinal cord compression. Increased size of the retrodental pannus can exacerbate the neurologic deterioration. Anterior removal of dens and pannus followed by posterior fusion has been proposed in such situations as a method to relieve spinal cord compression.
  
  
  METHODS
  Twenty-two patients with atlantoaxial instability and verified pannus on magnetic resonance imaging underwent posterior fusion of the upper cervical spine. These patients were followed 12 to 75 months after surgery by clinical, radiologic, and magnetic resonance imaging evaluations. The size of the pannus was compared before and after surgery.
  
  
  RESULTS
  In all patients, the retrodental pannus had significantly decreased or disappeared postoperatively.
  
  
  CONCLUSIONS
  Pannus reduction occurred even in patients whose disease was active or progressing, supporting the hypothesis that the pannus is more a reactive fibrous tissue resulting from instability rather than a direct consequence of the inflammatory process itself.
authors.affiliation: Schulrhess Klinik, Spine Unit, Zürich, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Grob
authors.forename: R
authors.initials: R
authors.lastname: Würsch
authors.forename: W
authors.initials: W
authors.lastname: Grauer
authors.forename: J
authors.initials: J
authors.lastname: Sturzenegger
authors.forename: J
authors.initials: J
authors.lastname: Dvorak
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000401:mortality / Q000473:pathology*; D001268:Atlanto-Axial Joint / Q000601:surgery*; D001933:Brain Stem / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D013117:Spinal Cord Compression / Q000209:etiology* / Q000401:mortality / Q000601:surgery; D013123:Spinal Fusion; D016896:Treatment Outcome