Disc Herniation in Cervical Fracture Subluxation

Abstract

Abstract Previous reports of computed tomographic scan with contrast myelography in cervical spinal cord injury have shown a rate of disc herniation of less than 5%. We hypothesized that injuries associated with forces adequate to cause bone or ligamentous injury in the region of the disc space could be associated with higher and more significant rates of disc herniation. Thirty-seven consecutive traumatic midcervical fracture subluxations were reviewed. Fracture subluxation was defined by fracture of the facet joints, pedicles, or vertebral bodies or more than 3.5 mm subluxation from C2-C3 to C7-T1. Reduction was achieved in 97% and was not associated with neurological deterioration. On the basis of plain films, tomograms, and plain computed tomographic scans, the injuries were classified as flexion dislocation, flexion compression, compression burst, or extension injuries. Twenty-five computed tomographic scans with contrast myelograms and one magnetic resonance imaging scan were obtained. All patients with partial neurological deficits were studied. A herniated disc was defined as that which deformed the thecal sac and/or nerve roots. Retrospectively, a neuroradiologist reviewed the studies for the presence of herniated disc. Disc herniation was seen at the level of injury in 9 (35%) patients and not seen in other patients. Forty-seven percent of the patients with partial deficits had herniated discs. Herniated discwas seen most frequently in flexion dislocation and flexion compression injuries. Three patients (20%) with partial deficits underwent discectomy. Patients with partial spinal cord injury and discectomy, on average, improved more than other patients with partial spinal cord injury. The authors conclude that: 1) herniated discs occur frequently in cervical fracture subluxation and are clinically significant; 2) disc herniation is associated with flexion dislocation and flexion compression injuries; 3) neuroimaging studies should be obtained in all patients with cervical fracture subluxation and neurological deficit to rule out compressive discs.