title: Frictional torque and wear of retrieved hip prostheses: a comparison between alumina/PE and Co-Cr/PE prostheses.
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.
authors.affiliation: Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, Kanagawa 227-8501, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kusaba
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kuroki
authors.forename: Saiji
authors.initials: S
authors.lastname: Kondo
authors.forename: Isao
authors.initials: I
authors.lastname: Hirose
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ito
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Shirasaki
authors.forename: Tetsuta
authors.initials: T
authors.lastname: Tateishi
authors.forename: Jörg
authors.initials: J
authors.lastname: Scholz
mesh_terms: D000328:Adult; D000368:Aged; D000537:Aluminum Oxide; D002858:Chromium Alloys; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011475:Prosthesis Failure; D019415:Torque
chemical_list: D002858:Chromium Alloys; D020959:Polyethylene; D000537:Aluminum Oxide