Tenascin-C levels in pseudosynovial fluid of loose hip prostheses.
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.
Hasegawa
M
M
Department of Orthopaedic Surgery, Mie University Faculty of Medicine, Japan. masahase@clin.medic.mie-u.ac.jp
Sudo
A
A
Nagakura
T
T
Hirata
H
H
Kinoshita
N
N
Yoshida
T
T
Uchida
A
A
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*
D019063:Tenascin