title: Porous cups with and without hydroxylapatite-tricalcium phosphate coating: 23 matched pairs evaluated with radiostereometry.
abstract: Migration, wear, and presence of radiolucencies were studied in 23 matched pairs of patients operated with porous-coated acetabular cups with additional screw fixation. All implants had the same type of titanium fiber mesh. In each pair, one of the cups was plasma-sprayed with a coating consisting of 70% hydroxylapatite (HA) and 30% tricalcium phosphate (TCP). Radiostereometric analysis up to 2 years after the operation revealed smaller rotations around the horizontal axis in cups with HA/TCP coating. The migration of the cup center was not significantly influenced. Evaluation of femoral head penetration in 12 of the matched pairs did not reveal any significant difference. Immediately after operation, implants with HA/TCP coating had more central radiolucencies, which, despite minimal migration, disappeared during the follow-up. The clinical results did not differ between the 2 groups. The findings of less tilting and diminishing radiolucencies in the cups with HA/TCP coating suggest a more complete ingrowth of bone and a better sealing of the interface.
authors.affiliation: Department of Orthopaedics, Sahlgren University Hospital, Göteborg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Thanner
authors.forename: J
authors.initials: J
authors.lastname: Kärrholm
authors.forename: P
authors.initials: P
authors.lastname: Herberts
authors.forename: H
authors.initials: H
authors.lastname: Malchau
mesh_terms: D001863:Bone Screws; D002130:Calcium Phosphates; D016022:Case-Control Studies; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D016062:Porosity; D011474:Prosthesis Design; D011859:Radiography; D013997:Time Factors; D014025:Titanium
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; D014025:Titanium; C485829:calcium phosphate, dibasic, anhydrous