title: Stability of Uncemented Cups - Long-Term Effect of Screws, Pegs and HA Coating: A 14-Year RSA Follow-Up of Total Hip Arthroplasty.
abstract: Screws, pegs and hydroxyapatite-coating are used to enhance the primary stability of uncemented cups. We present a 14-year follow-up of 48 hips randomized to four groups: press-fit only, press-fit plus screws, press-fit plus pegs and hydroxyapatite-coated cups. Radiostereometric migration measurements showed equally good stability regardless cup augmentation. The mean wear rate was high, 0.21 mm/year, with no differences between the groups. Seven hips had radiographical osteolysis but only in hips with augmented cups. Cups without screw-holes compared with cups with screw-holes resulted in better clinical outcome at the 14-year follow-up. Thus, augmentation of uncemented cups with screws, pegs, or hydroxyapatite did not appear to improve the long-term stability compared with press-fit only.
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopedics), Umeå University, Umeå, Sweden.
authors.forename: Volker T C
authors.initials: VT
authors.lastname: Otten
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopedics), Umeå University, Umeå, Sweden.
authors.forename: Sead
authors.initials: S
authors.lastname: Crnalic
authors.affiliation: Department of Orthopedics, Oslo University Hospital, Ullevål, Oslo, Norway.
authors.forename: Stephan M
authors.initials: SM
authors.lastname: Röhrl
authors.affiliation: Perth Orthopedic Institute, University of Western Australia, Perth, Australia.
authors.forename: Bo
authors.initials: B
authors.lastname: Nivbrant
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopedics), Umeå University, Umeå, Sweden.
authors.forename: Kjell G
authors.initials: KG
authors.lastname: Nilsson
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000706:statistics & numerical data*; D001863:Bone Screws / Q000706:statistics & numerical data; D017886:Durapatite; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis
chemical_list: D017886:Durapatite
keywords: THA; clinical outcome; cup; migration; radiostereometry (RSA); wear