title: Subsidence of stand-alone cervical carbon fiber cages.
abstract: OBJECTIVE
  To investigate the number of subsidences of inserted cervical carbon fiber cages and to define predictive factors for subsidence.
  
  
  METHODS
  All patients treated for a cervical herniated disc and fusion with a cervical carbon fiber cage between January 2002 and December 2003 were retrospectively identified. The radiological examinations were reviewed, and, especially, the presence of subsidence was noted. Possible predictive factors for subsidence were determined before the investigation.
  
  
  RESULTS
  In 69 patients, there were 96 cages inserted, of which 29.2% subsided. Of all factors investigated, only smoking seemed to be predictive for subsidence, whereas insertion at C6 to C7 clearly had a higher risk at subsidence. Subsidence was not related to outcome or fusion.
  
  
  CONCLUSIONS
  Although the high number of subsidence of cages has never been described before, clinical outcome and fusion rate is comparable with the literature.
authors.affiliation: Department of Neurosurgery, Radboud University, Nijmegen Medical Centre, Nijmegen, The Netherlands. r.bartels@nch.umcn.nl
authors.forename: Ronald H M A
authors.initials: RH
authors.lastname: Bartels
authors.forename: Roland D
authors.initials: RD
authors.lastname: Donk
authors.forename: Ton
authors.initials: T
authors.lastname: Feuth
mesh_terms: D000328:Adult; D002244:Carbon / Q000009:adverse effects; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008422:Materials Testing / Q000379:methods; D008875:Middle Aged; D019736:Prostheses and Implants; D011859:Radiography; D012189:Retrospective Studies
chemical_list: D002244:Carbon