title: Anterior cervical screw extrusion leading to acute upper airway obstruction: case report.
abstract: METHODS
  Case report of late postoperative complication.
  
  
  BACKGROUND
  There have been a number of reports of migration and extrusion of cervical fusion instrumentation. The majority of such cases have a benign outcome. To our knowledge, cervical instrumentation extrusion resulting in prevertebral abscess and acute airway obstruction has not been reported.
  
  
  METHODS
  A 56-year-old man who had undergone a prior C3-C6 anterior cervical decompression and fusion presented to a hospital with dysphagia and acute airway obstruction requiring an emergency tracheostomy. His neck radiograph showed that a C6 screw was missing compared to prior films. Magnetic resonance imaging showed a large prevertebral abscess anterior to C2-C7 causing complete upper airway obstruction.
  
  
  RESULTS
  He underwent surgical drainage of the abscess and had a good neurologic recovery.
  
  
  CONCLUSIONS
  We report a case of acute upper airway obstruction from prevertebral abscess, likely secondary to a loosened anterior cervical screw penetrating the prevertebral soft tissue. In contrast to case reports in the literature involving instrumentation extrusion with a usually benign outcome, our case presented with a life-threatening condition.
authors.affiliation: Division of Neurosurgery, Department of Anesthesiology, University of Toronto, Ontario, Canada. david.wong@uhn.on.ca
authors.forename: David T
authors.initials: DT
authors.lastname: Wong
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
authors.forename: Eric M
authors.initials: EM
authors.lastname: Massicotte
mesh_terms: D000402:Airway Obstruction / Q000209:etiology* / Q000473:pathology; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000601:surgery*; D019299:Decompression, Surgical / Q000009:adverse effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000473:pathology; D011475:Prosthesis Failure; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation