title: Polyetheretherketone (PEEK) intervertebral cage as a cause of chronic systemic allergy: a case report.
abstract: BACKGROUND
  Polyetheretherketone (PEEK) is an organic polymer thermoplastic with strong mechanical and chemical resistance properties. It has been used in industry to fabricate items for demanding applications such as bearings, piston parts, compressor plate valves, and cable insulation. Since the early 1980s, polyetheretherketone polymers have been increasingly used in orthopedic and spinal surgery applications. Numerous studies and years of clinical experience have confirmed the biocompatibility of this material.
  
  
  OBJECTIVE
  The purpose of the study was to report a case of chronic systemic allergy after anterior cervical decompression and fusion (ACDF) and implantation of an intervertebral PEEK cage, with resolution of symptoms after removal of PEEK cage.
  
  
  METHODS
  This study is a case report with clinical evidence for allergy to PEEK.
  
  
  METHODS
  The methods involve clinical findings and review of current literature.
  
  
  RESULTS
  After ACDF and implantation of an intervertebral PEEK cage, the patient had developed an angioedema-like picture marked by severe redness, itching, swelling of his tongue, and skin thickening. A skin patch test was positive for PEEK. Removal of the implant resulted in the resolution of his allergy symptoms shortly after surgery.
  
  
  CONCLUSIONS
  Tissue reactions to PEEK are extremely rare. Herein, we present the first report of a chronic allergic response to interbody PEEK material.
authors: Center for Spine Health, Department of Neurosurgery, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
authors: Andres L
authors: AL
authors: Maldonado-Naranjo
authors: Center for Spine Health, Department of Neurosurgery, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
authors: Andrew T
authors: AT
authors: Healy
authors: Center for Spine Health, Department of Neurosurgery, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA. Electronic address: kalfasi@ccf.org.
authors: Iain H
authors: IH
authors: Kalfas
mesh_terms: D001577:Benzophenones; D002574:Cervical Vertebrae / Q000601:surgery*; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007659:Ketones / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000009:adverse effects*; D011108:Polymers; D019736:Prostheses and Implants / Q000009:adverse effects*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols
keywords: Allergy; Hypersensitivity; Implant; PEEK; Polyetheretherketone; Spine