title: European multidisciplinary consensus statement on the use and monitoring of metal-on-metal bearings for total hip replacement and hip resurfacing.
abstract: BACKGROUND
  There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking.
  
  
  OBJECTIVE
  An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders.
  
  
  METHODS
  Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting.
  
  
  RESULTS
  The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥36mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 μg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2-7 μg/L.
  
  
  CONCLUSIONS
  This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels.
  
  
  METHODS
  Level V, expert opinion/agreement conference.
authors.affiliation: University Hospital Carl Gustav Carus Dresden, Orthopaedics, Fetscherstr. 74, 01307 Dresden, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Hannemann
authors.forename: A
authors.initials: A
authors.lastname: Hartmann
authors.forename: J
authors.initials: J
authors.lastname: Schmitt
authors.forename: J
authors.initials: J
authors.lastname: Lützner
authors.forename: A
authors.initials: A
authors.lastname: Seidler
authors.forename: P
authors.initials: P
authors.lastname: Campbell
authors.forename: C P
authors.initials: CP
authors.lastname: Delaunay
authors.forename: H
authors.initials: H
authors.lastname: Drexler
authors.forename: H B
authors.initials: HB
authors.lastname: Ettema
authors.forename: E
authors.initials: E
authors.lastname: García-Cimbrelo
authors.forename: H
authors.initials: H
authors.lastname: Huberti
authors.forename: K
authors.initials: K
authors.lastname: Knahr
authors.forename: J
authors.initials: J
authors.lastname: Kunze
authors.forename: D J
authors.initials: DJ
authors.lastname: Langton
authors.forename: W
authors.initials: W
authors.lastname: Lauer
authors.forename: I
authors.initials: I
authors.lastname: Learmonth
authors.forename: C H
authors.initials: CH
authors.lastname: Lohmann
authors.forename: M
authors.initials: M
authors.lastname: Morlock
authors.forename: M A
authors.initials: MA
authors.lastname: Wimmer
authors.forename: L
authors.initials: L
authors.lastname: Zagra
authors.forename: K P
authors.initials: KP
authors.lastname: Günther
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D003035:Cobalt; D005060:Europe; D006622:Hip Prosthesis; D006801:Humans; D061825:Metal-on-Metal Joint Prostheses; D015207:Osteoarthritis, Hip / Q000601:surgery; D010316:Particle Size
chemical_list: D003035:Cobalt