Supra acetabular bone mineral density measurements after hip resurfacing arthroplasty at short term follow up.

Implantation of a cementless press-fit acetabular cup during hip arthroplasty alters stress transfer to the periacetabular bone, resulting in stress shielding of cancellous bone and enhanced load transfer to cortical bone. Theoretically, the thicker, stiffer and larger acetabular cup of a hip resurfacing may increase periacetabular bone stress shielding. We attempted to assess the matter (at a minimum of 2 years after surgery) by measuring any difference in supra acetabular bone mineral density (BMD) between the side implanted with a thick monoblock cobalt-chromium (Co-Cr) acetabular component during hip resurfacing (HR) and the opposite non-operated side.