The risk factors inducing spinal cord injury in cervical myelopathy patients with mild to moderate cervical cord compression

English Keywords:Cervical vertebra  Spinal cord compression  Symptoms and signs  Imaging  Risk factors

English Abstract:

  【Abstract】 Objectives: To investigate the risk factors inducing spinal cord injury in cervical myelopathy patients with mild to moderate cervical cord compression. Methods: From November 2008 to November 2011， 68 patients(male∶female=37∶31) with mild to moderate cervical cord compression were included in this retrospective analysis. There were 32 single-segment cases, 22 double-segment cases and 14 three-segment cases. All of these cases underwent anterior-posterior， lateral， excessive flexion and extension cervical spine X-ray, CT and MRI. All patients were divided into two groups according to the symptoms and signs of myelopathy. Group A included 30 patients without clinical features of myelopathy. Group B included 38 patients with cervical spondylotic myelopathy. Age, gender, duration of disease, the number of segments involved, the Torg ratio at the most severe cord compression level, the ROM of cervical spine, cervical segmental instability, C2-C7 lofrdosis angle, the direction of spinal cord compression and high signal incidence were compared between the two groups. Results: No differences were found in terms of age, gender, duration of disease, the number of segments involved between the two groups. The mean Torg ratio at the most severe cord compression level was 90.3% and 83.6%, respectively(P＜0.05); the mean ROM of cervical spine was 47.5° and 44.1°, respectively(P＞0.05); the cervical segmental instability was 23.3% and 65.8%, respectively(P＜0.05); the mean C2-C7 lordosis was 14.1° and 14.1°, respectively(P＞0.05); the central type cord compression was observed in 19 patients of group A and 17 patients of group B, whereas the imcomplete central type cord compression was observed in 11 patients of group A and 21 patients of group B(P＞0.05); the high signal incidence was 13.3% and 86.9%, respectively(P＜0.05). Conclusions: Cervical segmental instability and spinal cord high intensity signal are the risk factors in cervical myelopathy with mild to moderate cervical cord compression, but a larger Torg ratio is a protective factor. It is still remained unclear that the direction of spinal cord compression, cervical total curvature and range of motion affect the appearance of spinal cord injury.