The association between cervical sagittal balance parameters and clinical outcomes after single-level surgery for cervical radiculopathy and/or stenosis: A systematic review and meta-analysis.

Introduction: The relationship between cervical sagittal balance parameters and clinical outcomes after single-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy and/or stenosis remains controversial. Research question: This meta-analysis was conducted to assess the evidence. Material and methods: Seven databases were searched through August 2025 for longitudinal studies that reported the correlation between sagittal balance and clinical outcomes. Stratified meta-analyses were conducted for the different sagittal balance parameters and clinical outcomes, accounting for the timing of assessment (preoperative, postoperative, or change scores) using the random-effects models. Results: Seven studies (with 723 patients in total) out of 693 unique studies met the inclusion criteria. A greater Cobbs angle of the target level (lordosis) appeared to be associated with a lower (better) postoperative Neck Disability Index (NDI) (pooled Pearson's r = -0.13, 95% CI: 0.23 to -0.02), while correlations with of C2-C7 angle, cSVA, T1 slope and T1 slope minus C2-C7 lordosis with NDI were not significant. No significant pooled correlations were found between postoperative C2-C7 angle and Visual Analogue Scale (VAS) arm- or neck pain. Non-pooled results demonstrated that a greater pre-operative odontoid incidence was associated with less arm and neck pain (r = -0.27; p = 0.01) and a more favorable NDI (r = -0.24; p = 0.03), and that a higher C2-C7 angle was associated with a more favorable Japanese Orthopaedic Association score (r = 0.40; p = 0.02). Discussion and conclusion: A greater postoperative Cobb angle at the target level may improve outcomes after ACDF. Further studies in larger, diverse populations are needed to confirm and generalize the results.