title: Bone scintigraphic appearance of asymptomatic hydroxyapatite-coated hip arthroplasties.
abstract: To obtain information about the bone scintigraphic appearance of a hydroxyapatite (HA)-coated proximal femoral implant, this examination was performed on 24 patients with a clinically and radiologically successful femoral implant in hip arthroplasty. The prosthesis had a proximal HA coating for supplementary fixation. The patients' mean age was 50.3 years (range, 28-65 years) at operation. The interval from the operation to the scintigraphy ranged from 6 months to 5.5 years (mean, 2.2 years). Scintigraphy was performed using 99mTc-medronic acid. Quantitative counts were recorded in 4 zones: 3 along the length of the implant (trochanteric region with HA coating, midprosthesis, and distal tip) and 1 below the prosthesis. The results were expressed as ratios using the nonoperated femur as a control value. The results demonstrated that the mean activities in all 4 zones were increased relative to the untreated side. The highest activity was observed in the region around the prosthetic tip, with an elevation of 46% above the control value. This activity showed a significant decline over time. The counts recorded in the trochanteric region, where the implant was coated with HA, were 20% above the control value and similar to those seen in its adjacent noncoated midprosthetic region. In the trochanteric region, however, the activity did not show a decline over the follow-up period.
authors.affiliation: Tampere University Hospital, Department of Surgery, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Moilanen
authors.forename: G
authors.initials: G
authors.lastname: Scott
authors.forename: M
authors.initials: M
authors.lastname: Newell
authors.forename: N
authors.initials: N
authors.lastname: Garvie
authors.forename: M A
authors.initials: MA
authors.lastname: Freeman
mesh_terms: D000328:Adult; D000368:Aged; D001672:Biocompatible Materials; D017886:Durapatite; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D019275:Radiopharmaceuticals; D017886:Durapatite; D013669:Technetium Tc 99m Medronate