title: Tenascin-C levels in pseudosynovial fluid of loose hip prostheses.
abstract: OBJECTIVE
  Aseptic loosening is one of the most important problems that can occur after total hip arthroplasty (THA). In this study, we analysed levels of large tenascin-C (TN-C) variants and compared them in pseudosynovial fluid from patients with aseptic loosening after THA with those in synovial fluid from patients undergoing primary THA (control).
  
  
  METHODS
  Pseudosynovial fluid samples (n = 24) were obtained by aspiration at the time of revision THA performed due to aseptic loosening. Synovial fluid samples (n = 12) were obtained by aspiration at the time of primary THA. Expression of TN-C splice variants was examined using immunoblotting. TN-C levels were measured using an enzyme-linked immunosorbent assay (ELISA) system that we developed previously.
  
  
  RESULTS
  Western blotting showed the presence of large TN-C variants in pseudosynovial fluid of artificial joints with loosening. TN-C levels were approximately three times higher in pseudosynovial fluid of loose artificial joints (median 151.9 ng/mL) than in synovial fluid controls (median 50.1 ng/mL) (p = 0.035).
  
  
  CONCLUSIONS
  Levels of TN-C including large variant subunits are elevated in pseudosynovial fluid of loose artificial joints, indicating that TN-C is a useful novel biochemical marker of loose hip prostheses.
authors.affiliation: Department of Orthopaedic Surgery, Mie University Faculty of Medicine, Japan. masahase@clin.medic.mie-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
authors.forename: A
authors.initials: A
authors.lastname: Sudo
authors.forename: T
authors.initials: T
authors.lastname: Nagakura
authors.forename: H
authors.initials: H
authors.lastname: Hirata
authors.forename: N
authors.initials: N
authors.lastname: Kinoshita
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: A
authors.initials: A
authors.lastname: Uchida
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000378:metabolism* / Q000601:surgery; D011475:Prosthesis Failure; D013582:Synovial Fluid / Q000378:metabolism*; D019063:Tenascin / Q000378:metabolism*
chemical_list: D019063:Tenascin