title: Failure of total hip implants: metals and metal release in 52 cases.
abstract: BACKGROUND
  The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity.
  
  
  OBJECTIVE
  To assess cobalt, nickel and chromium(VI) release from, and the metal composition of, failed metal-on-ethylene total hip replacements.
  
  
  METHODS
  Implant components from 52 revision cases were evaluated with spot tests for free nickel, cobalt, and chromium (VI) ions. Implant composition was determined with X-ray fluorescence spectroscopy, and information on the reason for revision and complications in relation to surgery was collected from the medical charts when possible (72%). For 10 implants, corrosion was further characterized with scanning electron microscopy.
  
  
  RESULTS
  We detected cobalt release from three of 38 removed femoral heads and from one of 24 femoral stems. Nickel release was detected from one of 24 femoral stems. No chromium(VI) release was detected.
  
  
  CONCLUSIONS
  We found that cobalt and nickel were released from some failed total hip arthroplasties, and corrosion was frequently observed. Metal ions and particles corroded from metal-on-polyethylene may play a role in the complex aetiopathology of implant failure.
authors.affiliation: Department of Orthopaedic Surgery, Aarhus University Hospital, DK-8000, Aarhus, Denmark.
authors.forename: Stig S
authors.initials: SS
authors.lastname: Jakobsen
authors.forename: Carola
authors.initials: C
authors.lastname: Lidén
authors.forename: Kjeld
authors.initials: K
authors.lastname: Søballe
authors.forename: Jeanne D
authors.initials: JD
authors.lastname: Johansen
authors.forename: Torkil
authors.initials: T
authors.lastname: Menné
authors.forename: Lennart
authors.initials: L
authors.lastname: Lundgren
authors.forename: David
authors.initials: D
authors.lastname: Bregnbak
authors.forename: Per
authors.initials: P
authors.lastname: Møller
authors.forename: Morten S
authors.initials: MS
authors.lastname: Jellesen
authors.forename: Jacob P
authors.initials: JP
authors.lastname: Thyssen
mesh_terms: D002857:Chromium / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D003343:Corrosion; D006622:Hip Prosthesis; D006801:Humans; D009532:Nickel / Q000737:chemistry*; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013499:Surface Properties
chemical_list: D002857:Chromium; D003035:Cobalt; D009532:Nickel; D020959:Polyethylene
keywords: chromium; cobalt; metal allergy; nickel; spot test; total joint replacement