Evaluation of changes in cervical sagittal balance and clinical parameters in patients undergoing two-level anterior cervical discectomy and fusion

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is an effective method in treating cervical sagittal imbalance and spine deformations. OBJECTIVES: The aim of this work was to assess whether changes of the Cobb angle, sagittal vertical axis (SVA) and T1 slope parameters affect the outcomes of surgical treatment. MATERIAL AND METHODS: A prospective study was performed in 30 patients qualified for surgical treatment for cervical degenerative disc disease. The ACDF was performed on 2 levels. Every patient underwent an X-ray examination before surgery and 3 months after the procedure. The following parameters were assessed: the T1 slope, the angle of cervical lordosis, the SVA distance, quality of life assessed using the Neck Disability Index (NDI), and perceived pain measurement assessed using the Visual Analogue Scale (VAS). RESULTS: The cervical lordosis angle significantly changed (p < 0.01) to an average of 11.52°. The SVA C2-C7 distance significantly decreased (p < 0.001) to an average of 21.06 mm. The value of the T1 slope angle did not change significantly before and after surgery (p = 0.706). After surgery, statistically significant improvement was achieved on the NDI scale for neck pain (p < 0.001) to an average of 9. The NDI score significantly decreased over time (p < 0.001), and this change was significantly related to the increased Cobb angle (p = 0.036). CONCLUSIONS: Improvement in cervical lordosis C2-C7 can improve the outcomes of surgical treatment. Preoperative analysis of X-rays and sagittal balance parameters may be beneficial for treatment outcomes.