title: Anterior cervical arthrodesis using a "stand alone" cylindrical titanium cage: prospective analysis of radiographic parameters.
abstract: METHODS
  Prospective, observational study.
  
  
  OBJECTIVE
  To evaluate biomechanical changes associated with cervical arthrodesis using a cylindrical titanium cage.
  
  
  BACKGROUND
  Anterior cervical discectomy and fusion (ACDF) is the "gold standard" for treating cervical disc disease. In an effort to avoid the morbidity associated with autogenous bone graft harvesting, cervical cages are used to achieve fusion. The cages should allow for restoration and maintenance of natural disc height, angulations, and displacements at the operated levels.
  
  
  METHODS
  Fifty-four patients underwent standard ACDF using a "stand alone" cylindrical cage implant. Lateral radiographic views of the cervical spine were obtained before surgery, on the first day postoperatively, and at 12 months postoperatively. Disc height, vertebral alignment, angle of lordosis, and range of motion at operated levels were quantified prospectively by distortion compensated Roentgen analysis.
  
  
  RESULTS
  At 12 months postoperatively, solid fusion was achieved but the cylindrical cage failed to preserve disc height, prevent kyphosis, and preserve natural intervertebral alignment. We observed significant cage subsidence and malalignment.
  
  
  CONCLUSIONS
  We noticed several unfavorable outcomes when performing an analysis of radiographic parameters after ACDF using a cylindrical titanium cage. Thus, the use of a "stand alone" cylindrical cage in ACDF should be considered with caution.
authors.affiliation: Department of Neurosurgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway. Frode.Kolstad@rikshospitalet.no
authors.forename: Frode
authors.initials: F
authors.lastname: Kolstad
authors.forename: Øystein P
authors.initials: ØP
authors.lastname: Nygaard
authors.forename: Hege
authors.initials: H
authors.lastname: Andresen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Leivseth
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007595:Joint Prosthesis / Q000009:adverse effects / Q000639:trends; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D055009:Spondylosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D017211:Treatment Failure