title: Lipopolysaccharide found in aseptic loosening of patients with inflammatory arthritis.
abstract: Aseptic loosening of orthopaedic implants occurs in the absence of clinical signs of infection. Nevertheless, bacterial endotoxins derived from subclinical infections, systemic sources, or the implant manufacturing process may contribute to aseptic loosening. Also, the rate of implant infection is greater in patients with inflammatory arthritis than in patients with osteoarthritis. We hypothesized that lipopolysaccharide, the classic endotoxin derived from gram-negative bacteria, is more prevalent in periprosthetic tissue surrounding aseptically loose implants in patients with inflammatory arthritis than in patients with osteoarthritis. To test this, we used a modified Limulus amebocyte assay not affected by beta-glucan-like molecules in mammalian tissues. Lipopolysaccharide rarely was detected in periprosthetic tissue from patients with osteoarthritis and aseptic loosening (one of six patients). In contrast, lipopolysaccharide was detected despite the absence of any clinical signs of infection in peri-prosthetic tissue from all four patients with inflammatory arthritis (rheumatoid arthritis, juvenile rheumatoid arthritis, and systemic lupus erythematosus). Lipopolysaccharide also was detected in two patients with gram-negative infections, who were included as positive control subjects. Endotoxins derived from low-grade or systemic bacteremia may be important contributors to aseptic loosening particularly in patients with autoimmune conditions such as inflammatory arthritis.
authors.affiliation: Departments of Orthopaedics, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, OH, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Nalepka
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lee
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
authors.forename: Randall E
authors.initials: RE
authors.lastname: Marcus
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Edward M
authors.initials: EM
authors.lastname: Greenfield
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000378:metabolism*; D019643:Arthroplasty, Replacement; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007595:Joint Prosthesis; D008070:Lipopolysaccharides / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000378:metabolism* / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000601:surgery; D011475:Prosthesis Failure
chemical_list: D008070:Lipopolysaccharides