C2–C7 sagittal alignment on lateral cervical X-rays and its correlation with neck pain, disability, and neurological symptoms

BackgroundCervical sagittal alignment is essential for proper load distribution and neural function. Alterations in the C2-C7 lordotic angle or sagittal vertical axis (SVA) may contribute to pain, functional decline, or neurological symptoms, but their relative clinical significance remains unclear.ObjectiveTo examine associations between C2-C7 lordotic angle, sagittal vertical axis (SVA), and clinical outcomes.MethodsThis retrospective cross-sectional study analyzed 130 outpatients undergoing lateral cervical radiography for neck pain. Patients were classified into normal lordosis (≥10 °) and hypolordosis (40 mm). Outcomes included Numeric Rating Scale (NRS), Neck Disability Index (NDI), and patient-reported neurological symptoms.ResultsHypolordosis was significantly associated with higher Numeric Rating Scale (NRS) and Neck Disability Index (NDI) scores, but neurological symptoms did not differ by lordosis. Increasing sagittal vertical axis (SVA) correlated strongly with disability and neurological deficits. Patients with sagittal vertical axis (SVA) > 40 mm had elevated odds of arm numbness (OR ≈ 13.8) and weakness (OR = 9.0; multivariate OR ≈ 8.1) compared with sagittal vertical axis (SVA) ≤ 20 mm. Multivariate analyses identified lordotic angle as the strongest predictor of pain, whereas sagittal vertical axis (SVA) was the key determinant of disability and neurological symptoms.ConclusionThe C2-C7 lordotic angle and sagittal vertical axis (SVA) play complementary roles: lordosis predicts neck pain, while sagittal vertical axis (SVA) reflects disability and neurological risk. Routine assessment of both, particularly sagittal vertical axis (SVA), may aid clinical decision-making in cervical spine disorders.