1. Lundbeck foundation Centre for Fast-track Hip and Knee Surgery, Aarhus - Denmark
2. Department of Orthopaedic Surgery, Aarhus University Hospital, Aarhus - Denmark
3. Department of Orthopaedic Surgery, Silkeborg Regional Hospital, Silkeborg - Denmark
4. Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus - Denmark
5. Department of Orthopaedic Surgery, Copenhagen University Hospital Hvidovre, Hvidovre - Denmark