 Indications for use of the H1 HRA in this investigation will be patients with end-stage hip disease who are candidates for primary hip arthroplasty using either a metal-on-metal hip resurfacing or a ceramic-on- ceramic THR. Typically they will be younger 70 years and active males and females with end-stage hip osteoarthritis, avascular necrosis of the femoral head, post-traumatic osteoarthritis or developmental dysplasia of the hip DDH. 