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Journal of Long-Term Effects of Medical Implants

ISSN for PRINT: 1050-6934

Institutional price:	$1021.00
Issues per year:	6

Best Paper Award Selection - Editorial Board Site

2002, Volume12

74 pages

Issue price - $175.00

Frictional Torque and Wear of Retrieved Hip Prostheses: A Comparison Between Alumina/PE and Co-Cr/PE Prostheses

Atsushi Kusaba, M.D.
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501 Japan

Yoshikatsu Kuroki, M.D.
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501 Japan

Saiji Kondo, M.D.
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501 Japan

Isao Hirose, M.D.
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501 Japan

Yuichi Ito, M.D.
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501 Japan

Yoshio Shirasaki, Ph.D.
Department of Biomechanics, National Engineering Laboratory, 1-2 Namiki, Tsukuba, Ibaragi 305-8504 Japan

Tetsuta Tateishi, Ph.D.
Department of Biomechanics, National Engineering Laboratory, 1-2 Namiki, Tsukuba, Ibaragi 305-8504 Japan

Jorg Scholz, M.D.
Department of Orthopaedic Surgery, Auguste-Viktoria Hospital, 125 Rubensstrasse, D-12157 Berlin, Germany

ABSTRACT

Frictional torque and wear were measured in 67 retrieved cups with internal diameters of 32 mm. Thirty cups were combined with alumina heads and 37 were combined with metal heads. A lower prevalence of cup loosening was observed in alumina-polyethylene implants than in metal-polyethylene implants. No relation between frictional torque and stability of implants was detected for either type, whereas retrieved cups of alumina—polyethylene implants showed lower frictional torque than those of metal-polyethylene implants. Less wear was observed in the cups of alumina-polyethylene implants (0.13 mm/y) than in those of metal—polyethylene implants (0.19 mm/y). Less wear was observed in cups without loosening than in those with loosening in both types. These results suggest that wear has a greater influence on the stability of cups than frictional torque.