Characterization of mode II-wear particles and cytokine response in a human macrophage-like cell culture.
Informations about wear particles in metallosis (mode II wear) and their effects in vitro and in vivo are limited. The aim of this study was to characterize wear particles obtained intraoperatively and to analyse their effects on cytokine response in an established human macrophage-like cell culture model.


METHODS
Wear particles were obtained intraoperatively from four patients with metallosis resulting from CrCoMo/PE/TiAIV-implants (mode II wear) (3 knee, 1 hip prosthesis). After purification, particles were characterized regarding to their composition and size (particle size analyser, electron microscopy, edx-analysis, histological slices). The effects of particles on the release of cytokines (PDGF, IL-1beta, IL-8, TNF alpha) were determined in an established human macrophage-like cell culture system by ELISA-assays.


RESULTS
The metal wear particles consisted of TiAIV with a mean size of 0.1 +/- 0.15 microm, independent of the prosthesis location. CrCoMo particles could not be detected. In the cell culture model 1456 x 10(8) particles per 1 x 10(6) macrophages released maximum amounts of TNFalpha (8-fold) and IL-8 and IL-1beta (5-fold) while the survival rate of the cells was more than 90 percent. A particle-dependent increase of PDGF-levels could not be detected.


CONCLUSIONS
As already shown for mode I wear particles (contact between primary bearing surfaces), also mode II wear particles cause release of bone resorbing cytokines in a macrophage-like cell culture model. Because their local and systemic effects in vivo are still not completely understood, we recommend a complete removal of wear particles in cases of metallosis to avoid possible immunological reactions of the body as well as periprosthetic osteolysis.
Rolf
Olaf
O
Department of Orthopedics, König-Ludwig-Haus, University of Würzburg, Brettreichstr. 11, D-97074 Würzburg, Germany.
Baumann
Bernd
B
Sterner
Thomas
T
Schütze
Norbert
N
Jakob
Franz
F
Eulert
Jochen
J
Rader
Christof Paul
CP
D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D001672:Biocompatible Materials / Q000009:adverse effects; D002460:Cell Line; D016207:Cytokines / Q000276:immunology*; D005260:Female; D005549:Foreign-Body Reaction / Q000276:immunology* / Q000473:pathology*; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects*; D008264:Macrophages / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D010316:Particle Size; D011475:Prosthesis Failure; D014025:Titanium / Q000009:adverse effects*
D000497:Alloys; D001672:Biocompatible Materials; D016207:Cytokines; C031462:titanium alloy (TiAl6V4); D014025:Titanium