title: Polyethylene wear particles in synovial fluid after total knee arthroplasty.
abstract: The aims of the current study were to examine polyethylene particles in synovial fluid at an early stage, and to compare a newly introduced medial pivot total knee prosthesis with an established posterior-stabilized total knee prosthesis. Synovial fluid was obtained 1 year after knee arthroplasty from 17 patients with well-functioning prostheses (22 knees, 11 posterior-stabilized prostheses and 11 medial pivot prostheses) under complete sterile conditions. Polyethylene particles were isolated and analyzed by scanning electron microscopy. Particle size (equivalent circle diameter) was 0.78 +/- 0.08 microm (mean +/- standard error) in posterior-stabilized prostheses and 0.67 +/- 0.06 microm in medial pivot prostheses. Particle shape (aspect ratio) was 2.30 +/- 0.22 in posterior-stabilized prostheses and 1.90 +/- 0.16 in medial pivot prostheses. The total numbers of particles were 1.16 +/- 0.57 x 10(8) in posterior-stabilized prostheses and 9.01 +/- 2.95 x 10(6) in medial pivot prostheses. Particles were smaller and rounder in medial pivot prostheses than in posterior-stabilized prostheses, but the differences were not significant. The difference in the common logarithm of particle number was significant. The medial pivot prosthesis generated less wear particles than the posteriorstabilized prosthesis, and these findings may have an impact on the incidence of osteolysis and aseptic loosening.
authors.affiliation: Department of Orthopaedic Surgery, Osaka City University Medical School, Osaka, Japan. yminoda@med.osaka-cu.ac.jp
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Minoda
authors.forename: Akio
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Iwaki
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Miyaguchi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kadoya
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ohashi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamano
authors.forename: Kunio
authors.initials: K
authors.lastname: Takaoka
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010316:Particle Size; D020959:Polyethylene; D011475:Prosthesis Failure; D013582:Synovial Fluid
chemical_list: D020959:Polyethylene