title: [Histopathological diagnostic work-up of joint endoprosthesis-associated pathologies].
abstract: Increasing classes of joint implants and the combination of materials results in increased and wear-associated pathologies. According to the revised consensus classification, the following types can be recognized at conventional histological examination: Type I, particle-induced type; Type II, infection type; Type III, combination type; Type IV, indifferent type; Type V arthrofibrotic type; Type VI, allergic/immunological/toxic adverse reactions and Type VII, bone pathologies. Wear particles are histopathologically characterized according to the Krenn particle algorithm which focuses on a descriptive identification of wear particles and the differentiation of other nonwear-related particles. Type VII is considered histologically when there is evidence of a perivascular/interstitial lymphocytic CD20- and CD3-positive infiltrate, presence of mast cells and eosinophils, and tissue necrosis/infarction associated with implant wear material. Since wear particle-induced toxicity cannot be differentiated with certainty from hypersensitivity/allergic reaction on histological examination, immunological-allergological and clinical data should be used as supplementary criteria for the differential diagnosis. Tissue sampling should be performed from periprosthetic soft tissue with location mapping and when feasible also from bone tissue. Additional information regarding the type of implant and clinical, radiological, immunological, and microbiology data should be available to the pathologist. Further immunohistochemical studies are recommended in the following settings: infection (CD15, CD20, CD68); prosthesis-associated arthrofibrosis (β‑catenin); allergic/immunologic/toxic adverse reactions (CD20, CD3, CD4, CD8, CD117 and for T‑cell characterization T‑bet, GATA-3, and FOXP3).
authors.affiliation: MVZ-Zentrum für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Str. 5, 54296, Trier, Deutschland. krenn@patho-trier.de.
authors.forename: V
authors.initials: V
authors.lastname: Krenn
authors.affiliation: Department of Pathology and Laboratory Medicine, Hospital for Special Surgery, New York, USA.
authors.forename: G
authors.initials: G
authors.lastname: Perino
authors.affiliation: Sigmund Freud PrivatUniversität Berlin, Berlin, Deutschland.
authors.forename: V T
authors.initials: VT
authors.lastname: Krenn
authors.affiliation: VMscope GmbH Berlin, Berlin, Deutschland.
authors.forename: S
authors.initials: S
authors.lastname: Wienert
authors.affiliation: MVZ-Zentrum für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Str. 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: MVZ-Zentrum für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Str. 5, 54296, Trier, Deutschland.
authors.forename: F
authors.initials: F
authors.lastname: Hopf
authors.affiliation: Pathologisch-bakteriologisches Institut, Otto Wagner Spital, Wien, Österreich.
authors.forename: M
authors.initials: M
authors.lastname: Huber
mesh_terms: D003937:Diagnosis, Differential; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology*; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D007595:Joint Prosthesis / Q000009:adverse effects*; D008670:Metals / Q000009:adverse effects*; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000473:pathology*
chemical_list: D008670:Metals
keywords: Adverse reaction; Allergic reaction; Classification; Implants; Synovitis