title: Failure of a polyether-ether-ketone expandable interbody cage following transforaminal lumbar interbody fusion.
abstract: OBJECTIVE
  Expandable cages are a more recent option for maintaining or restoring disc height and segmental lordosis with transforaminal lumbar interbody fusion (TLIF). Complications associated with expandable cages have not yet been widely reported. We report a case of postoperative failure of a polyether-ether-ketone (PEEK) expandable interbody device used during TLIF.
  
  
  METHODS
  A 50-year-old man presented with severe back and right leg pain after undergoing L4-5 and L5-S1 TLIFs with expandable cages and L3-S1 posterior instrumented fusion. Imaging showed retropulsion of a portion of the interbody cage into the spinal canal causing nerve compression. Displacement occurred in a delayed manner. In addition, pseudoarthrosis was present.
  
  
  RESULTS
  The patient underwent re-exploration with removal of the retropulsed wafer and redo fusion.
  
  
  CONCLUSIONS
  Expandable cages are a recent innovation; as such, efficacy and complication data are limited. As with any new device, there exists potential for mechanical failure, as occurred in the case presented.
authors.affiliation: University of Michigan Medical School, Ann Arbor, MI, USA.
authors.forename: Isaac C
authors.initials: IC
authors.lastname: Stein
authors.forename: Khoi D
authors.initials: KD
authors.lastname: Than
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Chen
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Wang
authors.forename: Paul
authors.initials: P
authors.lastname: Park
mesh_terms: D001577:Benzophenones; D001672:Biocompatible Materials; D020878:Device Removal; D006801:Humans; D007659:Ketones; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols; D011108:Polymers; D011475:Prosthesis Failure / Q000009:adverse effects / Q000209:etiology; D012086:Reoperation; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols