1. Radiology and Nuclear Medicine, Cantonal Hospital Lucerne, Lucerne, Switzerland
2. Orthopedic Surgery and Traumatology, Cantonal Hospital Lucerne, Lucerne, Switzerland
3. Radiology, Cantonal Hospital Zug, Baar, Switzerland
4. Orthopedic Surgery, Cantonal Hospital Lucerne, Sursee, Switzerland
5. Orthopedic Surgery, Cantonal Hospital Lucerne, Wolhusen, Switzerland
6. Department of Orthopedic Surgery, Columbia University Medical Center/ Presbyterian Hospital, New York, United States