From the *Department of Orthopedic Surgery, National Hospital, Oslo, the†Department of Neurosurgery, St. Olav’s Hospital, Trondheim, the‡Coast Hospital for Physical Medicine and Rehabilitation, Stavern, the§Department of Physical Medicine and Rehabilitation, Ullevaal University Hospital, Oslo, the∥Department of Neurosurgery, University North Norway, Tromsø, and the¶Department of Biological and Medical Psychology, University of Bergen, Norway.