1. Department of Anaesthesiology; Horsens Regional Hospital; Horsens Denmark
2. Department of Orthopaedic Surgery; Horsens Regional Hospital; Horsens Denmark
3. Department of Orthopaedic Surgery; Aarhus University Hospital; Aarhus Denmark
4. Department of Anaesthesiology; Aarhus University Hospital; Aarhus Denmark
5. Danish Pain Research Center; Aarhus University Hospital; Aarhus Denmark