Characteristics of polyethylene wear particles isolated from synovial fluid after mobile-bearing and posterior-stabilized total knee arthroplasties

✍ Scribed by Minoda, Yukihide ;Kobayashi, Akio ;Iwaki, Hiroyoshi ;Miyaguchi, Masatsugu ;Kadoya, Yoshinori ;Ohashi, Hirotsugu ;Takaoka, Kunio

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 152 KB
• Volume: 71B
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.b.30005

✦ Synopsis

Abstract

The size, shape, and number of polyethylene wear particles found in synovial fluids of patients 1 year after implantation of 22 well‐functioning total knee prostheses (11 contemporary mobile‐bearing type, 11 posterior‐stabilized type) were determined. Polyethylene wear particles were isolated from synovial fluids and examined by scanning electron microscopy. Particle size (equivalent circle diameter) was 0.81 ± 0.12 μm (mean ± standard error) in mobile‐bearing types and 0.78 ± 0.08 μm in posterior‐stabilized types. Particle shape (aspect ratio) was 1.94 ± 0.13 in mobile‐bearing types and 2.30 ± 0.22 in posterior‐stabilized types. Total numbers of particles were (1.75 ± 1.02) × 10^8^ in mobile‐bearing and (1.16 ± 0.57) × 10^8^ in posterior‐stabilized types. The differences in these parameters between the two groups were not statistically significant. In the early stages after surgery, contemporary mobile‐bearing types were comparable to posterior‐stabilized types in terms of polyethylene wear‐particle generation. The present results do not support the proposition that has been put forward in the literature; namely, that the contemporary mobile‐bearing design has an advantage, in terms of the polyethylene wear rate. These data suggest that the advantage of complete conformity in the femoro‐tibial articulating surface of contemporary mobile‐bearing design may be offset by wear of the mobile undersurface and slot, apart from the articulating surface. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 1–6, 2004