K-line tilt: A novel potential predictive indicator for the effectiveness of conservative cervical spondylotic radiculopathy management

Background: Cervical spondylotic radiculopathy is a prevalent degenerative cervical spine disease. K-line tilt is a recently discovered cervical spine sagittal plane parameter. However, the relationship between K-line tilt and conservative cervical spondylotic radiculopathy management remains unknown. Methods: We retrospectively analyzed the clinical records of 188 patients with cervical spondylotic radiculopathy who were conservatively treated at our hospital from May 2016 to May 2022. The effective and ineffective conservative treatment groups included 90 patients and 98 patients, respectively. Cervical sagittal parameters, including K-line tilt, C2–C7 sagittal plane axial vertical distance (C 2 –C 7 SVA), T1 slope, and C2–C7 lordosis, were measured and compared. Multiple logistic regressions were conducted to analyze risk factors for effective conservative treatment. Results: The results revealed that K-line tilt and C2–C7 lordosis were significantly different for the effective and ineffective groups ( P < 0.05). Multifactorial regression analysis revealed a K-line tilt of <6.11° as a risk factor for effective conservative cervical spondylotic radiculopathy treatment ( P < 0.05), and receiver operating characteristic curves demonstrated a moderate diagnostic value with an area under the curve of 0.77. Conclusions: This study confirms K-line tilt (<6.11°) as a potential risk factor for the effectiveness of conservative cervical spondylotic radiculopathy treatment. Conservative treatment may be less effective when the K-line tilt of the cervical spine is >6.11°.