1. Department of Spine Surgery and Scoliosis Center, Schön Klinik Neustadt, Neustadt, Germany
2. Department of Orthopedic Surgery, Rehabilitation and Regenerative Medicine, LMU Munich, Munich, Germany
3. Department of Orthopaedic Surgery, Klinik St. Georg, Hamburg, Germany
4. Agaplesion Ev. Bathildiskrankenhaus Bad Pyrmont, Bad Pyrmont, Germany
5. Department of Orthopedic Surgery, Katholisches Krankenhaus Hagen – St.-Josefs-Hospital, Hagen, Germany