Magnetic resonance evaluation of the intervertebral disc, spinal ligaments, and spinal cord before and after closed traction reduction of cervical spine dislocations

Study Design, A prospective clinical study using magnetic resonance imaging of the cervical spine in a consecutive series of patients with cervical sp ine dislocations. Objectives. To determine the incidence of intervertebral disc herniations a nd injury to the spinal ligaments before and after awake closed traction re duction of cervical spine dislocations. Summary of Background Data. Prior series in which the prereduction imaging of disc herniations in the dislocated cervical spine are described have bee n anecdotal and have involved small numbers of patients. In addition, no un iform clinical criteria to define the presence of an intervertebral disc he rniation in the dislocated cervical spine has been described. The incidence of disc herniations in the unreduced dislocated cervical spine is unknown. Methods. Eleven consecutive patients with cervical spine dislocations who m et the clinical criteria for an awake closed traction reduction had preredu ction and postreduction magnetic resonance imaging. Using strict clinical c riteria for the definition of an intervertebral disc herniation, the presen ce or absence of disc herniation, spinal ligament injury, and cord injury w as determined. Neurologic status before, during, and after the closed reduc tion maneuver was documented. Results, Disc herniations were identified in 2 of 11 patients before reduct ion. Awake closed traction reduction was successful in 9 of the 11 patients . Of the nine patients with a successful closed reduction, two had disc her niations before reduction, and five had disc herniations after reduction. N o patient had neurologic worsening after attempted awake closed traction re duction. Conclusions. The process of closed traction reduction appears to increase t he incidence of intervertebral disc herniations. The relation of these find ings, however, to the neurologic safety of awake closed traction reduction remain unclear.