Correlation Between Parameters of Intervertebral Disc and Cervical Lordosis in Cervical Spondylotic Myelopathy

BACKGROUND: In cervical disc degeneration, cervical disc height (CDH) and cervical disc angle (CDA)have a certain but unidentified relationship with cervical lordosis (CL). This study aimed to reveal the relationship among CDH, CDA, and CL in patients diagnosed with cervical spondylotic myelopathy (CSM). MATERIAL/METHODS: A retrospective analysis was conducted using the data of 212 CSM patients (136 males and 76 females). According to CL angle, patients were classified into 2 groups: patients with CL ≤10° constituted Group 1 (n=102); patients with CL >10° constituted Group 2 (n=110). The CDH, CDA, and CL were measured using X-ray imaging. Pearson correlation analysis measured the correlation between CDH, CDA, and CL. Multiple linear regression was utilized to analyze the effects of CDH and CDA on CL. RESULTS: The CDAs in every level were higher in Group 2 than those in Group 1 (P<0.05).CDH and CDA gradually increased with the increase in vertebral level and dropped at C5–C6 level in both groups. We found statistically significant correlations between C3/4H, C4/5H, C3/4A,C4/5A, C5/6A, and C6/7Aand CL in Group 1 (P<0.05), and between C4/5H, C3/4A, and C4/5Aand CL in Group 2 (P<0.05). C3/4A and C4/5A predicted CL in Group 1 (adjusted R(2)=0.176, P<0.001), while C4/5A predicted CL with high sensitivity in Group 2 (adjusted R(2)=0.198, P<0.001). CONCLUSIONS: CDA contributes more than CDH to CL in CSM. Further studies are necessary to reveal the relationship between CL and cervical disc degeneration.