The annual implantation rate of hip prostheses is estimated to be about million worldwide, and the success rate is about 90 percent after 10 years post-operatively. The usual cause of failure is mechanical loosening of the implant. These loosened components can be detected as they migrate within the bone. Recently, accurate migration measuring techniques have been introduced, which are capable of detecting loosened components) and can identify these as future revisions, already within one year after the implantation. This has led to the hypothesis that loosening is dominated by factors which can be assessed immediately after the operation. The aim of this study is to investigate this hypothesis. Therefore, patient data, patient-specific computer simulation methods, and laboratory experiments are combined to determine which factors are responsible for early loosening of the component.