title: Degradation of hydroxyapatite coating on a well-functioning femoral component.
abstract: We carried out a histological study of a proximally hydroxyapatite (HA)-coated femoral component, retrieved after 9.5 years of good function. The HA coating had completely degraded. Bone was in direct contact with the titanium surface in all the areas which had been coated, with no interposing fibrous tissue. There were no signs of particles, third-body wear, adverse tissue reactions or osteolysis. Bone remodelling was evident by the presence of resorption lacunae; tetracycline labelling showed bone laid down six years after implantation. The loss of the HA-coating had no negative effect on the osseo-integration of the stem. We conclude that the HA coating contributes to the fixation of the implant and that its degradation does not adversely affect the long-term fixation.
authors.affiliation: Department of Orthopaedic Surgery, University of Otago, Dunedin, New Zealand.
authors.forename: N
authors.initials: N
authors.lastname: Aebli
authors.forename: J
authors.initials: J
authors.lastname: Krebs
authors.forename: D
authors.initials: D
authors.lastname: Schwenke
authors.forename: H
authors.initials: H
authors.lastname: Stich
authors.forename: P
authors.initials: P
authors.lastname: Schawalder
authors.forename: J C
authors.initials: JC
authors.lastname: Theis
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D017886:Durapatite; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery*; D010784:Photomicrography; D011475:Prosthesis Failure; D011859:Radiography
chemical_list: D017886:Durapatite