title: Neo-capsule tissue reactions in metal-on-metal hip arthroplasty.
abstract: BACKGROUND
  Modern-generation metal-on-metal articulations have a high wear resistance and may therefore be able to improve the long-term performance of artificial joints. However, the biological effects are still under debate. This study was undertaken to review the histopathological changes in neo-capsule tissues of different metal-on-metal hip arthroplasties.
  
  
  METHODS
  Neo-capsule tissue samples from 46 hips with modern second-generation metal-on-metal articulations (39 hip resurfacings and 7 non-cemented total hip replacements) with a variety of failure mechanisms were examined histopathologically and immunohistochemically.
  
  
  RESULTS
  A distinct lymphocytic infiltration was found in all cases with in situ times of more than 7 months, consisting of CD20-positive B-lymphocytes and CD3-positive T-lymphocytes and sometimes thinly distributed CD138-positive plasma cells without dominant T-cell or plasma cell infiltrates.
  
  
  CONCLUSIONS
  This distinct lymphocytic infiltration has not been reported in tissue analyses of metal- or ceramic-on-polyethylene hip replacements, and may therefore be considered to be a characteristic histological pattern of tissue reactions on metal particles and/or ions around metal-on-metal bearings.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Carl Gustav Carus, Dresden, Germany. Wolf-Christoph.Witzleb@uniklinikum-dresden.de
authors.forename: Wolf-Christoph
authors.initials: WC
authors.lastname: Witzleb
authors.forename: Uwe
authors.initials: U
authors.lastname: Hanisch
authors.forename: Nicole
authors.initials: N
authors.lastname: Kolar
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Guenther
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000473:pathology; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology; D008297:Male; D008670:Metals / Q000009:adverse effects; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D010316:Particle Size; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000382:microbiology / Q000473:pathology; D012086:Reoperation
chemical_list: D008670:Metals