title: The 6-year migration characteristics of a hydroxyapatite-coated femoral stem: a radiostereometric analysis study.
abstract: A prospective cohort of 30 patients undergoing primary total hip arthroplasty for treatment of osteoarthritis was enrolled in a study to characterize the migration behavior of a clinically successful cementless stem. At 6 years, the mean subsidence of the stem was 0.63 mm (range, -0.33 to 3.68 mm); the mean rotation into retroversion was 1.41° (range, -1.33° to 7.48°). No stems had additional subsidence of more than 0.25 mm between 6 months and 6 years. The resultant mean subsidence between 2 and 6 years was 0.03 mm, which is below the limit measurable by radiostereometric analysis. The data demonstrate that subsidence of this cementless stem occurs within the first 6 months, after which there is persistent stabilization.
authors.affiliation: Discipline of Orthopaedics and Trauma, University of Adelaide and Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Callary
authors.forename: David G
authors.initials: DG
authors.lastname: Campbell
authors.forename: Graham E
authors.initials: GE
authors.lastname: Mercer
authors.forename: Kjell G
authors.initials: KG
authors.lastname: Nilsson
authors.forename: John R
authors.initials: JR
authors.lastname: Field
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017886:Durapatite; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery*; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D007593:Joint Instability; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D011446:Prospective Studies; D011475:Prosthesis Failure / Q000639:trends*; D059869:Radiostereometric Analysis / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D017886:Durapatite