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

• Published in: The Journal of arthroplasty 2006-04, Vol.21 (3), p.344-352
• Main Authors: Sluimer, Judith C, Hoefnagels, Nicolette H M, Emans, Pieter J, Kuijer, Roel, Geesink, Rudolph G T
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Arthroplasty, Replacement, Hip; Biocompatible Materials; Bone Density; Durapatite; Female; Hip Prosthesis; Humans; Male; Middle Aged; Osteoarthritis, Hip - surgery; Pain, Postoperative - epidemiology; Prosthesis Design; Recovery of Function
• ISSN: 0883-5403
• DOI: 10.1016/j.arth.2005.06.015

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.