title: Perivascular lymphocytic infiltration is not limited to metal-on-metal bearings.
abstract: BACKGROUND
  Perivascular lymphocytic infiltration (PVLI) suggests an adaptive immune response. Metal hypersensitivity after THA is presumed associated with idiopathic pain and aseptic loosening, but its incidence and relationship to metallic wear leading to revision are unclear as are its presence and relevance in non-metal-on-metal arthroplasty.
  
  
  OBJECTIVE
  We compared (1) incidence and severity of PVLI in failed hip metal-on-metal (MoM) to non-MoM implants and TKA; (2) PVLI in MoM and non-MoM hip arthroplasty based on reason for revision; and (3) PVLI grade to diffuse lymphocytic infiltration (DLI) and tissue reaction to metal particles.
  
  
  METHODS
  We retrospectively examined incidence and severity of PVLI, DLI, and tissue reaction in periprosthetic tissue from 215 THA and 242 TKA revisions including 32 MoM hips.
  
  
  RESULTS
  Perivascular lymphocytic infiltration was present in more TKAs (40%) than overall hip arthroplasties (24%) without difference in severity. Compared to non-MoM hips, MoM bearings were more commonly associated with PVLI (59% versus 18%) and demonstrated increased severity (41% versus 3% greater than mild). Histologically, PVLI correlated (r = 0.51) with DLI, but not tissue reaction. In THA, PVLI was most commonly associated with idiopathic pain (70%) and aseptic loosening (54%) in MoM, and infection in all hip revisions (53%).
  
  
  CONCLUSIONS
  Perivascular lymphocytic infiltration is more extensive in revisions of MoM and in aseptic loosening, idiopathic pain, or infection but is also present in TKA, non-MoM, and different reasons for revision. It correlates with other signs of metal hypersensitivity, but not with histologic measures of metal particulate load.
  
  
  METHODS
  Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics, The Ohio State University, Columbus, OH, USA.
authors.forename: Vincent Y
authors.initials: VY
authors.lastname: Ng
authors.forename: Adolph V
authors.initials: AV
authors.lastname: Lombardi
authors.forename: Keith R
authors.initials: KR
authors.lastname: Berend
authors.forename: Michael D
authors.initials: MD
authors.lastname: Skeels
authors.forename: Joanne B
authors.initials: JB
authors.lastname: Adams
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D001672:Biocompatible Materials; D002465:Cell Movement; D020099:Coated Materials, Biocompatible; D005260:Female; D006621:Hip Joint / Q000473:pathology*; D006622:Hip Prosthesis; D006801:Humans; D007249:Inflammation; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D008670:Metals; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D012086:Reoperation; D012189:Retrospective Studies; D013314:Stress, Mechanical
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D008670:Metals