Bone Remodeling Around Porous Metal Cementless Acetabular Components
Received 8 September 2008; accepted 18 April 2009. published online 27 May 2009.
Abstract
Bone remodeling around cementless acetabular components after total hip arthroplasty has not been well characterized. A randomized, prospective study of total hip arthroplasty was performed comparing 2 cementless acetabular implants: a solid titanium and a more elastic porous tantalum design. Seventeen hips (9 porous tantalum, 8 titanium) underwent quantitative computed tomography at mean of 7.7 years, and adjacent bone mineral density (BMD) was calculated. The absolute and relative decrease in BMD from preoperative level was less in zones 9 to 15 mm adjacent to the porous tantalum compared to the titanium component (P ≤ .02) and predominated posterosuperiorly. The relative BMD increased in all regions adjacent to the porous tantalum component from 5% to 40% over the control. This data demonstrates stress-shielding likely occurs less around a highly porous metal implant of material with an elastic modulus similar to bone.
⁎Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut
†Department of Radiology, Mayo Clinic, Rochester, Minnesota
‡Department of Orthopaedic Surgery, Mayo Clinic, Rochester, Minnesota
Reprint requests: R. Michael Meneghini, MD, Department of Orthopaedic Surgery, University of Connecticut Health Center, Medical Arts and Research Building, 4th Floor, #4016, 263 Farmington Ave, Farmington, CT 06034-4037.
While the authors did not receive any benefits for this part of the study, benefits were received by Implex for the original study from which this cohort was taken. Therefore, it should be noted that benefits were received in support of this study from Implex. Also it should be noted that one or more of the authors have received royalties and payments from Implex/Zimmer.
ABSTRACT