title: Articulating polymethylmethacrylate (PMMA) spacers may have an immunomodulating effect on synovial tissue.
abstract: OBJECTIVE
  Tissue responses to debris formed by abrasion of polymethylmethacrylate (PMMA) spacers at two-stage revision arthroplasty for prosthetic joint infection are not well described. We hypothesised that PMMA debris induces immunomodulation in periprosthetic tissues.
  
  
  METHODS
  Samples of tissue were taken during 35 two-stage revision arthroplasties (nine total hip and 26 total knee arthroplasties) in patients whose mean age was 67 years (44 to 85). Fourier transform infrared microscopy was used to confirm the presence of PMMA particles. Histomorphometry was performed using Sudan Red and Haematoxylin-Eosin staining. CD-68, CD-20, CD-11(c), CD-3 and IL-17 antibodies were used to immunophenotype the inflammatory cells. All slides were scored semi-quantitatively using the modified Willert scoring system.
  
  
  RESULTS
  The mean CD-68 scores did not show any significant change during the six weeks between the stages. Perivascular and diffuse scores showed significant difference in CD-3, CD-20, CD-11(c) and IL-17. At the time of re-implantation, a shift in the pattern of the expression of dendritic cells towards a perivascular arrangement and towards the periphery of PMMA particles was observed. Positive microbiological cultures were found at the time of re-implantation in three patients. Five further revisions were required for other reasons.
  
  
  CONCLUSIONS
  Our results represent a biological reaction of the synovial tissues to spacers with a less diffuse expression of dendritic cells and an increased expression of perivascular lymphocytes. The use of spacers in two-stage revision for infection probably induces an immunomodulation of synovial tissues. Cite this article: Bone Joint J 2016;98-B:1062-8.
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery Cluster, National University Health System, 1E Kent Ridge Road, 119228, Singapore.
authors.forename: G
authors.initials: G
authors.lastname: Singh
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Deutloff
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Maertens
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Meyer
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Awiszus
authors.affiliation: Magdeburg-Stendal University of Applied Sciences, Breitscheidstr. 2, D-39114 Magdeburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Feuerstein
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Roessner
authors.affiliation: Otto-von-Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
authors.forename: C H
authors.initials: CH
authors.lastname: Lohmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015703:Antigens, CD / Q000378:metabolism; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001843:Bone Cements / Q000494:pharmacology*; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D056747:Immunomodulation / Q000187:drug effects / Q000276:immunology; D020381:Interleukin-17 / Q000378:metabolism; D007720:Knee Prosthesis; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000276:immunology / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000276:immunology / Q000601:surgery; D019904:Polymethyl Methacrylate / Q000494:pharmacology*; D016459:Prosthesis-Related Infections / Q000276:immunology*; D012086:Reoperation; D013583:Synovial Membrane / Q000276:immunology
chemical_list: D015703:Antigens, CD; D001843:Bone Cements; D020381:Interleukin-17; D019904:Polymethyl Methacrylate
keywords: 2-stage exchange arthroplasty; Cement spacer; Immunomudulation; Tissue response