title: Migration of porous press-fit cups in hip revision arthroplasty. A radiostereometric 2-year follow-up study of 60 hips.
abstract: The migration of 60 press-fit cups fixed with screws was evaluated by radiostereometric analysis for 2 years in 57 patients revised because of aseptic loosening. The mean proximal migration of the cup center increased continuously up to 0.36 mm (range, 0.0-1.6 mm), whereas the migration in the other directions reached a level at 0.3 to 0.4 mm after 6 months. Mean rotations of less than 1 degree were recorded. Factors influencing motions were cup size, use of bone-grafts, and position of the cup center in the vertical and horizontal directions. Compared with previous stereoradiographic studies of cemented revisions, the migration of the press-fit cup was smaller, however, still higher than previously reported for uncemented cups of the same design used in primary surgery.
authors.affiliation: Department of Orthopedics, Northern University Hospital, Umeå, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Nivbrant
authors.forename: J
authors.initials: J
authors.lastname: Kärrholm
authors.forename: I
authors.initials: I
authors.lastname: Onsten
authors.forename: A
authors.initials: A
authors.lastname: Carlsson
authors.forename: F
authors.initials: F
authors.lastname: Snorrason
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging* / Q000209:etiology; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016062:Porosity; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies