title: Comparison of two hydroxyapatite-coated femoral stems: clinical, functional, and bone densitometry evaluation of patients randomized to a regular or modified hydroxyapatite-coated stem aimed at proximal fixation.
abstract: Clinical function, bone mineral density (BMD), and radiographs of 80 randomly allocated, hydroxyapatite-coated femoral stems of two differing lengths were studied for 2 years. The short stem was optimized for proximal fixation. The predictive value of bone densitometry was also studied. After 2 years, significantly more bone apposition and a higher BMD percentage were observed in Gruen zone 7 of the short stem. We conclude that stem design can be enhanced to achieve more proximal fixation. However, we found a higher incidence of pain with the short stem, indicating a trade-off between increased proximal fixation and diminished overall mechanical stability. No strong correlations between clinical function and radiographic evaluation of remodeling were found with BMD, suggesting that dual-energy x-ray absorptiometry has no predictive value for short-term clinical outcome.
authors.affiliation: Orthopaedics Department, University Hospital Maastricht, Maastricht, The Netherlands.
authors.forename: Judith C
authors.initials: JC
authors.lastname: Sluimer
authors.forename: Nicolette H M
authors.initials: NH
authors.lastname: Hoefnagels
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Emans
authors.forename: Roel
authors.initials: R
authors.lastname: Kuijer
authors.forename: Rudolph G T
authors.initials: RG
authors.lastname: Geesink
mesh_terms: D015502:Absorptiometry, Photon; D019644:Arthroplasty, Replacement, Hip; D001672:Biocompatible Materials; D015519:Bone Density; D017886:Durapatite; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D010149:Postoperative Pain / Q000453:epidemiology; D011474:Prosthesis Design; D020127:Recovery of Function
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite