title: Retrieval analysis of PEEK rods for posterior fusion and motion preservation.
abstract: BACKGROUND
  The purpose of this study was to analyze explanted PEEK rod spinal systems in the context of their clinical indications. We evaluated damage to the implant and histological changes in explanted periprosthetic tissues.
  
  
  METHODS
  12 patients implanted with 23 PEEK rods were revised between 2008 and 2012. PEEK rods were of the same design (CD Horizon Legacy, Medtronic, Memphis TN, USA). Retrieved components were assessed for surface damage mechanisms, including plastic deformation, scratching, burnishing, and fracture. Patient history and indications for PEEK rod implantation were obtained from analysis of the medical records.
  
  
  RESULTS
  11/12 PEEK rod systems were employed for fusion at one level, and motion preservation at the adjacent level. Surgical complications in the PEEK cohort included a small dural tear in one case that was immediately repaired. There were no cases of PEEK rod fracture or pedicle screw fracture. Retrieved PEEK rods exhibited scratching, as well as impressions from the set screws and pedicle screw saddles. PEEK debris was observed in two patient tissues, which were located adjacent to PEEK rods with evidence of scratching and burnishing.
  
  
  CONCLUSIONS
  This study documents the surface changes and tissue reactions for retrieved PEEK rod stabilization systems. Permanent indentations by the set screws and pedicle screws were the most prevalent observations on the surface of explanted PEEK rods.
authors.affiliation: Drexel University, 3401 Market St, Suite 345, Philadelphia, PA, 19104, USA, skurtz@drexel.edu.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.forename: Todd H
authors.initials: TH
authors.lastname: Lanman
authors.forename: Genymphas
authors.initials: G
authors.lastname: Higgs
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Macdonald
authors.forename: Sigurd H
authors.initials: SH
authors.lastname: Berven
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Isaza
authors.forename: Eual
authors.initials: E
authors.lastname: Phillips
authors.forename: Marla J
authors.initials: MJ
authors.lastname: Steinbeck
mesh_terms: D000328:Adult; D001577:Benzophenones; D001863:Bone Screws; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006801:Humans; D016268:Internal Fixators; D055959:Intervertebral Disc Degeneration / Q000628:therapy; D007659:Ketones; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009038:Motion; D011092:Polyethylene Glycols; D011108:Polymers; D011446:Prospective Studies; D019736:Prostheses and Implants; D011859:Radiography; D016059:Range of Motion, Articular; D012086:Reoperation; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*
chemical_list: D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols