title: Anterior cervical discectomy and fusion: comparison of titanium and polyetheretherketone cages.
abstract: BACKGROUND
  Titanium (TTN) cages have a higher modulus of elasticity when compared with polyetheretherketone (PEEK) cages. This suggests that TTN-cages could show more frequent cage subsidence after anterior cervical discectomy and fusion (ACDF) and therefore might lead to a higher loss of correction. We compared the long term results of stand-alone PEEK- and TTN-cages in a comparable patient collective that was operated under identical operative settings.
  
  
  METHODS
  From 2002 to 2007 154 patients underwent single-level ACDF for degenerative disc disease (DDD). Clinical and radiological outcome were assessed in 86 eligible patients after a mean of 28.4 months. 44 patients received a TTN- and 42 patients a PEEK-cage.
  
  
  RESULTS
  Solid arthrodesis was found in 93.2% of the TTN-group and 88.1% of the PEEK-group. Cage subsidence was observed in 20.5% of the TTN- and 14.3% of the PEEK-group. A significant segmental lordotic correction was achieved by both cage-types. Even though a loss of correction was found at the last follow-up in both groups, it did not reach the level of statistical significance. Statistical analysis of these results revealed no differences between the TTN- and PEEK-group.When assessed with the neck disability index (NDI), the visual analogue scale (VAS) of neck and arm pain and Odom's criteria the clinical data showed no significant differences between the groups.
  
  
  CONCLUSIONS
  Clinical and radiological outcomes of ACDF with TTN- or PEEK-cages do not appear to be influenced by the chosen synthetic graft. The modulus of elasticity represents only one of many physical properties of a cage. Design, shape, size, surface architecture of a cage as well as bone density, endplate preparation and applied distraction during surgery need to be considered as further important factors.
authors.affiliation: Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Hindenburgdamm 20, Berlin, 12200, Germany. mario.cabraja@charite.de
authors.forename: Mario
authors.initials: M
authors.lastname: Cabraja
authors.forename: Soner
authors.initials: S
authors.lastname: Oezdemir
authors.forename: Daniel
authors.initials: D
authors.lastname: Koeppen
authors.forename: Stefan
authors.initials: S
authors.lastname: Kroppenstedt
mesh_terms: D000328:Adult; D000368:Aged; D001577:Benzophenones; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D016009:Chi-Square Distribution; D004185:Disability Evaluation; D017586:Diskectomy / Q000295:instrumentation*; D055119:Elastic Modulus; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000601:surgery*; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D007659:Ketones; D008141:Lordosis / Q000209:etiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology / Q000601:surgery; D016348:Osseointegration; D010147:Pain Measurement; D011092:Polyethylene Glycols; D011108:Polymers; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation*; D013997:Time Factors; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D014025:Titanium