Clinical and Radiological Outcome in a Series of Patients Treated by Anterior Cervical Discectomy and Fusion: Retrospective Controlled Study With 2 Different Stand-Alone Cages

Background: Cervical spine balance and alignment targets after cervical spine surgery are poorly established in patients with cervical spine degenerative disease surgically treated by anterior cervical discectomy and fusion (ACDF). The objective of the study is to determine the correlation between radiological and clinical outcomes in patients surgically treated by ACDF with 2 different stand -alone cervical cages.Methods: Clinical outcomes were evaluated using visual analog scale (VAS), Neck Disability Index (NDI), Nurick Scale, and Japanese Orthopedic Association score for myelopathy. Radiological evaluation included cervical and segmental Cobb angles, cervical sagittal vertical axis (cSVA), T1 slope (T1s), C0 -C2 angle, fusion rates, adjacent segment degeneration, and cage subsidence.Results: A total of 80 patients were included with an average age of 53 years. There was a statistically significant improvement in both clinical and radiological evaluations. There was a statistical significant correlation between cervical pain on cervical VAS and cSVA. There was a significant correlation between postoperative T1s and cSVA, related to the improvement in cervical angles. There was no significant difference in rates of fusion, adjacent segment changes, or reoperation between both cervical cages, and there was a higher rate of subsidence in the Aleutian group. There were significant differences between both groups on postoperative NDI and VAS, but this difference is not maintained during follow -up.Conclusions: Cervical sagittal balance is directly related to clinical outcome in patients with cervical spine degenerative disease. Both cervical implants analyzed were comparable in clinical and radiological outcomes.Clinical Relevance: There are important clinical and radiological parameters that should be taken into account for the analysis of the surgical outcome of patients treated by ACDF; this is one of the few studies that report the results with 2 different cervical cage designs. Level of Evidence: 4.