1. Institute of Biomechanics, TUHH Hamburg University of Technology, Hamburg, Germany
2. Department of Orthopaedic Surgery and Traumatology, Universidad Autónoma de Madrid, Madrid, Spain
3. Department of Orthopaedics and Traumatology, University Hospital Bonn, Bonn, Germany
4. London Implant Retrieval Centre, Royal National Orthopaedic Hospital, Stanmore, UK
5. Department of Orthopaedic Surgery, Heidelberg University Hospital, Heidelberg, Germany