The Changes Of Disc And Spinal Cord Injury Before And After Closed Traction Reduction Of Cervical Spinal Dislocation

BACKGROUND: cervical spine facet dislocation represents the serious trauma to the cervical spine. Patients with traumatic locked facets who demonstrated a high incidence of associated disc herniation documented on MRI.Treament of these injuries is directed at reduction to restore anatomic alignment of the cervical spine and stabilization of spine that avoids causeing or worsening neurologic deficits.Someone indicates that closed reduction of facet dislocation associated with disc rupture may result in increased spinal cord compression and neurological deficit. But most scholars consider that closed reduction is a safety and effective treatment,especially those who is able to cooperate with neurologic testing.AIM: To observe the disc and spinal cord injury before and after closed traction reduction of cervical spinal dislocation.Study the correlation between MRI and pathology of disc and spinal cord.METHODS: There were 46 cases with cervical spine facet dislocation,24 unilateral and 22 bilateral. All patients were undergone neurological function and cervical spine MRI examinnation before and after closed traction reduction.The disc herniation and spinal cord injury were compared. 14 canine models of cervical spine disloction were produced and examined by MRI.The findings were studied relativity with histology of the spinal cords and disc. RESULTS:. Awake closed traction reduction was done in 39 of 46 patients,and successful in 34 patients.7 of 33 patients had disc herniation,4 of 33 patients had disc disruption and 23 of patients had no disc injury before reduction .After closed traction reduction,6patients had simllar herniation,one patients had only significant smaller disc herniation comparing with before reduction.there were no new disc herniation after reducton.33 patients had no changes of spinal cord sign on MRI before and after closed traction reduction.One patients had incresse high density sign on MRI T2WI imaging.But there were no neurological worsening after reduction.14 Dogs were selected to duplicate cervical spinal facet dislocation model.9 dogs were successful . MRI revealed a loss of the normal signal from the nucleus pulposus of all the intervertebral disc of the injuried section.3 of 9 show a low signal on MRI T1WI and T2WI. pathology section show AF were flex and NP were almost integrity.6 of 9 show disc herination on MRI. pathology section show rupture of AF,NP disppeared or only fragment of cells can be seen.MRI show that cervical spinal cord sweling.Anlarged and diffuse contusion in T1WI, spotty higer mixed singal in T2WI were seen in 7 of 9. Pathology section show hemorrhage and edema in spinal cord,necrosis of part of neurons.2 of 9 show litter more higer single in T2WI on MRI,and pathology revealed hemorrhage in the white matter, edema in white matter and gray matter. CONCLUSION: 1. injuries of intervertebral disc were extremely common after facet dislocation.2. Skull traction reduction is a safety and effective treatment,It could not increase the disc herniation and cause further spinal cord injury.3.Patient with cervical spine dislocation can undergo immediate closed traction reduction without delaying to obtain a prereduction MRI when they are awake and are able to cooperate with neurological testing.4. This model can almost make SCI.MRI show that cervical spinal cord were sweling. Anlarged and diffuse contusion on T1WI, spotty higer mixed singal on T2WI. Pathology section show hemorrhage and edema in spinal cord,necrosis of part of neurons.5. MRI revealed a loss of the normal signal from the nucleus pulposus of all the intervertebral disc of the injuried section. Pathology section show curve of AF or disc herniation.6. Spinal cord edema,hemorrhage were quite detectable by MRI,however,nerve cell degeneration and flammation were not visible on the MRI..7. The serious of SCI was related not only to disc herniation but also to other factors.