title: Proposal for a histopathological consensus classification of the periprosthetic interface membrane.
abstract: OBJECTIVE
  The introduction of clearly defined histopathological criteria for a standardised evaluation of the periprosthetic membrane, which can appear in cases of total joint arthroplasty revision surgery.
  
  
  METHODS
  Based on histomorphological criteria, four types of periprosthetic membrane were defined: wear particle induced type (detection of foreign body particles; macrophages and multinucleated giant cells occupy at least 20% of the area; type I); infectious type (granulation tissue with neutrophilic granulocytes, plasma cells and few, if any, wear particles; type II); combined type (aspects of type I and type II occur simultaneously; type III); and indeterminate type (neither criteria for type I nor type II are fulfilled; type IV). The periprosthetic membranes of 370 patients (217 women, 153 men; mean age 67.6 years, mean period until revision surgery 7.4 years) were analysed according to the defined criteria.
  
  
  RESULTS
  Frequency of histopathological membrane types was: type I 54.3%, type II 19.7%, type III 5.4%, type IV 15.4%, and not assessable 5.1%. The mean period between primary arthroplasty and revision surgery was 10.1 years for type I, 3.2 years for type II, 4.5 years for type III and 5.4 years for type IV. The correlation between histopathological and microbiological diagnosis was high (89.7%), and the inter-observer reproducibility sufficient (85%).
  
  
  CONCLUSIONS
  The classification proposed enables standardised typing of periprosthetic membranes and may serve as a tool for further research on the pathogenesis of the loosening of total joint replacement. The study highlights the importance of non-infectious, non-particle induced loosening of prosthetic devices in orthopaedic surgery (membrane type IV), which was observed in 15.4% of patients.
authors.affiliation: Institute für Pathologie, University Hospital Charité, Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Morawietz
authors.forename: R-A
authors.initials: RA
authors.lastname: Classen
authors.forename: J H
authors.initials: JH
authors.lastname: Schröder
authors.forename: C
authors.initials: C
authors.lastname: Dynybil
authors.forename: C
authors.initials: C
authors.lastname: Perka
authors.forename: A
authors.initials: A
authors.lastname: Skwara
authors.forename: J
authors.initials: J
authors.lastname: Neidel
authors.forename: T
authors.initials: T
authors.lastname: Gehrke
authors.forename: L
authors.initials: L
authors.lastname: Frommelt
authors.forename: T
authors.initials: T
authors.lastname: Hansen
authors.forename: M
authors.initials: M
authors.lastname: Otto
authors.forename: B
authors.initials: B
authors.lastname: Barden
authors.forename: T
authors.initials: T
authors.lastname: Aigner
authors.forename: P
authors.initials: P
authors.lastname: Stiehl
authors.forename: T
authors.initials: T
authors.lastname: Schubert
authors.forename: C
authors.initials: C
authors.lastname: Meyer-Scholten
authors.forename: A
authors.initials: A
authors.lastname: König
authors.forename: P
authors.initials: P
authors.lastname: Ströbel
authors.forename: C P
authors.initials: CP
authors.lastname: Rader
authors.forename: S
authors.initials: S
authors.lastname: Kirschner
authors.forename: F
authors.initials: F
authors.lastname: Lintner
authors.forename: W
authors.initials: W
authors.lastname: Rüther
authors.forename: I
authors.initials: I
authors.lastname: Bos
authors.forename: C
authors.initials: C
authors.lastname: Hendrich
authors.forename: J
authors.initials: J
authors.lastname: Kriegsmann
authors.forename: V
authors.initials: V
authors.lastname: Krenn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005549:Foreign-Body Reaction / Q000145:classification / Q000209:etiology / Q000473:pathology*; D015743:Giant Cells, Foreign-Body / Q000473:pathology; D006097:Granulation Tissue / Q000473:pathology; D006621:Hip Joint / Q000473:pathology; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000150:complications / Q000473:pathology; D012086:Reoperation