The outcome of cementless total hip arthroplasty (THA) in aging women is challenged by impaired bone quality as it can jeopardize implant fixation and stability. Implant migration can be evaluated by means of radiostereometric analysis (RSA), which represents the first object of interest in this thesis. The second object of interest is the positron emission tomography with computed tomography (PET/CT) imaging of adverse reaction to metal debris (ARMD). Metal-on-metal hip arthroplasties generate wear debris that causes periprosthetic tissue inflammation and damage. PET/CT detects sites of inflammation, and therefore could be applicable in the diagnostics of ARMD. 

In the first two studies, aging females suffering from hip osteoarthritis underwent cementless THA. Preoperative bone mineral density (BMD) assessment showed low BMD in most of the subjects. The first study evaluated the stability of the femoral stems in a nine-year follow-up. The second placebo-controlled trial evaluated the effects of an antiresorptive drug, zoledronic acid, on femoral stem migration and periprosthetic BMD in a four-year follow-up. The third exploratory, controlled, open-label study characterized the PET/CT imaging findings of symptomatic ARMD patients with [18F]FDG and [68Ga]Citrate. 

The femoral stems did not show significant late migration. Zoledronic acid did not inhibit early implant migration but it reduced periprosthetic bone loss. The cementless femoral stems are stabile even in aging women. The inflammatory ARMD is better visualized with [18F]FDG than with [68Ga]Citrate.