title: [Supramacroparticulate polyethylene in inflammation of synovial-like interface membranes: Characterization and suggested nomenclature].
abstract: BACKGROUND
  The identification of particles of prosthesis material components in the histopathological diagnosis of synovialitis is of great importance in the evaluation of implant failure.
  
  
  METHODS
  In histopathological particle algorithms, polyethylene (PE) particles with a maximum length of less than 100 µm are designated with the term macroparticles; however, a systematic investigation and characterization are lacking.
  
  
  RESULTS
  In SLIM knee specimens (n = 24) a minimum value of 210 µm and a maximum value of 2100 µm were measured; the mathematical mean length varied between 235 µm and 1416 µm. In SLIM hip specimens (n = 11) the minimum value was 290 µm and the maximum value was 1806 µm; the mean length varied between 353 and 1726 µm. Because of this conspicuous size, and to distinguish from PE macroparticles, the designation PE supra-macroparticulate is suggested. This new terminology acknowledges the fact that these PE particles are visible under magnification (e.g., × 12.5) and also macroscopically. The particles were also indirectly proven as there were completely separate and optically clear, column-shaped cavities corresponding to the shape of the PE particles (PE vacuoles). The life of the prosthesis is highly variable at between 12 and 300 months. In all cases loosening of the prosthesis, misalignment of the PE components, and/or damage to the PE inlay occurred.
  
  
  CONCLUSIONS
  The cause and existence of these supra-macroparticulate PE particles (more than 100 µm) is still unclear. A mechanical malfunction seems probable and should be discussed. In prostheses with short lives the proof of supra-macroparticulate PE in SLIM could be a sign of an early mechanical problem. In the wider histopathological particle algorithm supra-macroparticulate PE was considered to fall in the category of macroparticles and should be considered in the histopathological diagnosis of implant failure.
authors.affiliation: MVZ für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Straße 5, 54296, Trier, Deutschland. krenn@patho-trier.de.
authors.forename: V
authors.initials: V
authors.lastname: Krenn
authors.affiliation: MVZ für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Straße 5, 54296, Trier, Deutschland.
authors.forename: F
authors.initials: F
authors.lastname: Hopf
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität, München, Deutschland.
authors.forename: P
authors.initials: P
authors.lastname: Thomas
authors.affiliation: Klinikum Mittelbaden, Baden-Baden, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Thomsen
authors.affiliation: Abteilung Wissenschaft, CeramTec GmbH, Plochingen, Deutschland.
authors.forename: S
authors.initials: S
authors.lastname: Usbeck
authors.affiliation: Hospital for Special Surgery/HSS, New York, USA.
authors.forename: F
authors.initials: F
authors.lastname: Boettner
authors.affiliation: MVZ für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Straße 5, 54296, Trier, Deutschland.
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.affiliation: MVZ für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Straße 5, 54296, Trier, Deutschland.
authors.forename: D
authors.initials: D
authors.lastname: Saberi
authors.affiliation: Universitätsspital Basel, Basel, Schweiz.
authors.forename: T
authors.initials: T
authors.lastname: Hügle
authors.affiliation: Pathologisch-bakteriologisches Institut, Otto Wagner Spital, Wien, Österreich.
authors.forename: M
authors.initials: M
authors.lastname: Huber
authors.affiliation: Abteilung Wissenschaft, CeramTec GmbH, Plochingen, Deutschland.
authors.forename: L
authors.initials: L
authors.lastname: Scheuber
authors.affiliation: Zentrum für Orthopädie und Unfallchirurgie, Universitätsmedizin Mainz, Mainz, Deutschland.
authors.forename: J C
authors.initials: JC
authors.lastname: Hopf
authors.affiliation: Labor für Biomechanik und Implantatforschung, Klinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Heidelberg, Heidelberg, Deutschland.
authors.forename: J P
authors.initials: JP
authors.lastname: Kretzer
mesh_terms: D005260:Female; D006621:Hip Joint / Q000737:chemistry*; D006801:Humans; D007595:Joint Prosthesis; D007719:Knee Joint / Q000737:chemistry*; D008297:Male; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry; D020959:Polyethylene / Q000032:analysis / Q000737:chemistry*; D013583:Synovial Membrane / Q000737:chemistry*; D013585:Synovitis / Q000378:metabolism* / Q000473:pathology; D009626:Terminology as Topic
chemical_list: D052638:Particulate Matter; D020959:Polyethylene
keywords: Algorithms; Particle size; Polarization microscopy; Prostheses and implants; Prosthesis failure