The correlation analysis of the degree of cervical intervertebral disc herniation associated with cervical X-ray radiography index

Abstract

Objective To investigate the relationship of the related parameters of X-ray and the severity of cervical spinal cord compression caused by disc herniation in patients with single segment spondylotic myelopathy. Methods Clinical data of sixty paitents with single segment spondylotic myelopathy in the First Affiliated Hospital of Anhui Medical University from August 2012 to March 2014 were retrospectively analyzed. All the patients, aged from 42 to 65 (58.4±9.3), were male. According to the compression ratio (E value) of cervical spinal cord in sagittal MRI images, all the patients were firstly divided into group Ⅰ, Ⅱ and Ⅲ. The ratio of cervical spinal crosscutting area (S1) to effective cervical canal crosscutting area (S0) in cross-sectional imagings of cervical spine MRI was then calculated to reflect the degree of intervertebral disc herniation. Furthermore, the following indicators in cervical X-ray in different postures were measured for each case: the range of motion of the responsibility of intervertebral space (B value), the height of the anterior of intervertebral space (D value), Cobb angle of C2-7, and the area of intervertebral foramen (M value). Linear correlation regression was used to study the relationship of the severity of cervical spinal cord compression and the above observation indexes. Results There were significant differences in the ratio of S1/S0, E value, B value, D value, M value and Cobb angle of C2-7 among three groups (F values were 44.187, 112.789, 7.232, 3.778, 3.232 and 15.813, respectively. all P values<0.05). E value, B value, D value, M value and Cobb angle of C2-7 decreased with the increase of the ratio of S1/S0. These indicated that E value, B value, D value, M value and Cobb angle of C2-7 were negatively correlated with the ratio of S1 / S0 (R values were-0.821, -0.581, -0.378, -0.419 and -0.576, respectively, all P values<0.05). The multiple linear regression results showed that B value, D value and M value were the three independent factors of the ratio of S1/S0, and the prognostic equation of the ratio of S1/S0 was =118.955-1.348X1-2.850X2-0.541X3 (multiple correlation coefficient R=0.742, decision coefficient R2 =0. 550, F=22.841, P<0. 01). Conclusions The related indicators of B value, D value and M value in cervical vertebral X-ray of different positions are independent factors of intervertebral disc herniation in cervical spondylosis myelopathy, and have certain diagnostic effect for assessing the severity of single segmental intervertebral disc herniation in cervical spondylosis myelopathy. Accordind to these studies, the severity of cervical intervertebral disc herniation can be predicated by measuring the B value, D value and M value. Key words: Cervical spondylosis; Intervertebral disc displacement; Tomography, X-Ray