Evaluation of the effectiveness of surgical treatment using the one-level ACDF method based on changes in the parameters of the sagittal balance of the cervical spine

Introduction
Anterior cervical fixation is one of the most effective methods of treating cervical discopathy. The following parameters are distinguished to assess cervical sagittal balance: cervical lordosis angle, T1 slope, and sagittal vertical axis.
Aim of the research: To assess the impact of the increase in the cervical lordosis angle on the other parameters of sagittal balance and on the effects of surgical treatment.

Material and methods
Thirty patients were qualified for surgical treatment with the method of a single-level ACDF. An X-ray examination was taken before and 3 months after surgery. The following parameters were analysed: T1 slope, sagittal vertical axis, and cervical lordosis angle. The perceived pain was assessed by analysing the results of the NDI questionnaire and the VAS scale.

Results
After surgical treatment, the Cobb angle changed statistically significantly (p = 0.001), on average 11.79°. The SVA C2-7 distance did not change significantly (p = 0.697), with a mean of 22.82 mm after surgery. The value of the T1 slope angle increased to 27.38° (p < 0.001). There was a significant reduction in the NDI scale (p < 0.001) and in the VAS scale (p < 0.001), but no correlation with changes in the sagittal balance parameters was demonstrated.

Conclusions
The change in cervical sagittal balance seems to be an important prognostic factor in the assessment of the effectiveness of surgical treatment. The individual parameters showed mutual dependencies. The correction of balance parameters after single-level ACDF stabilization does not significantly affect the result of surgical treatment (NDI, VAS). However, this issue requires further research.