Management of cervical spinal cord injury in ankylosing spondylitis: the intervertebral disc as a cause of cord compression.

Twenty-one patients with universal syndesmophytosis due to ankylosing spondylitis were identified in a consecutive series of 1578 patients with acute spine and spinal cord injuries. They were predominantly male, older than spinal cord-injured patients in general, and most were injured by falls. Approximately one-half were managed by halo-vest immobilization alone with good clinical and radiological outcomes. The remainder required surgery either for recurrent dislocation or for spinal cord compression associated with neurological deterioration. Extradural hematoma, a recognized cause of spinal cord compression in ankylosing spondylitis patients with spinal fractures, was encountered in two patients. Herniated intervertebral disc as a cause of spinal cord compression in ankylosing spondylitis does not appear to have been previously reported and was recognized three times in the present series, once in association with extradural hematoma. The pathology of ankylosing spondylitis is such that the nucleus pulposus tends to be spared, allowing disc herniation to occur in the heavily ossified spine. In virtually all patients, satisfactory correction of the flexion deformity could be safely accomplished following spinal fracture. It is concluded that fracture/dislocations of the cervical spine should be managed initially by halo-vest immobilization, without prior traction and with careful incremental correction of flexion deformity. Decompression is performed as required for extradural hematoma or intervertebral disc herniation, and internal fixation is carried out for recurrent dislocation.