title: A large collar increases neck resorption in total hip replacement. 204 hips evaluated during 5 years.
abstract: We evaluated the effect of a prosthetic collar on the proximal femoral bone in 204 hips without any signs of loosening after 5 years. The patients were operated on at 5 centers, using different prosthetic designs, but the same cementing technique. Resorption was more often found in cases with a true and large collar (Lubinus, HD2, Scanhip) than in cases with a flanged or tapered stem (Charnley, Exeter). The resorption was also more pronounced with the former designs. It was concluded that, in spite of theoretical advantages, a large collar is not only unnecessary but may also have negative long-term effects.
authors.affiliation: Department of Orthopedics, Malmö University Hospital, Sweden.
authors.forename: A S
authors.initials: AS
authors.lastname: Carlsson
authors.forename: J
authors.initials: J
authors.lastname: Rydberg
authors.forename: R
authors.initials: R
authors.lastname: Onnerfält
mesh_terms: D000704:Analysis of Variance; D001843:Bone Cements; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000209:etiology*; D001862:Bone Resorption / Q000000981:diagnostic imaging / Q000209:etiology*; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D016017:Odds Ratio; D011474:Prosthesis Design; D011859:Radiography
chemical_list: D001843:Bone Cements