Total hip arthroplasty is one of the most successful and cost-effective surgical interventions in medicine1 and is the most effective treatment for osteoarthritis of the hip joint. Long-term studies of selected patient cohorts2-4 and the Scandinavian hip registries5,6 have demonstrated high survivorship rates after more than twenty years. On the basis of this success, total hip replacement is being performed on increasingly younger and more active patients. However, there are at least two problems that a young or active patient faces with regard to the prosthetic joint. First, the use of the implant is more intense in proportion to their physical activities7. Second, the patient's life expectancy is longer and the potential total number of loading cycles is increased proportionally.