Periprosthetic Bone Remodeling Around Uncemented Components in Total Hip Arthroplasty

This is a randomized clinical trial comparing two different uncemented femoral stems and two different uncemented sockets using Dual-energy x-ray absorptiometry, Radiostereometry and clinical evaluation. Hypothesis: 1. A short uncemented stem gives less periprosthetic bone resorption in the proximal femur than a conventional uncemented stem. 2. An uncemented acetabular component with a backside of three-dimensional Titanium porous construct gives less periprosthetic bone resorption than a backside covered with a conventional porous coating with Titanium-beads and a hydroxy-apatite layer.