K-Line Tilt

STUDY

DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of the study is to determine whether the K-line inclination angle can serve as a potential indicator for predicting the effectiveness of conservative treatment for single-level cervical radiculopathy.

SUMMARY OF BACKGROUND DATA: Cervical spondylotic radiculopathy (CSR) 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 CSR management remains unknown.

METHODS

Due to the need for detailed case data, we selected inpatients, and 188 patients who met the inclusion and exclusion criteria of the study were selected from May 2016 to May 2022. The effective and ineffective conservative treatment groups included 90 and 98 patients, respectively. Cervical sagittal parameters were measured and compared, including K-line tilt, C2-C7 sagittal plane axial vertical distance (C2-C7 SVA), T1 slope, and C2-C7 lordosis. Binary logistic regressions were conducted to analyze risk factors for effective conservative treatment.

RESULTS

The results revealed that K-line tilt and C2-C7 lordosis significantly differed for the effective and ineffective groups (P<0.05). Binary logistic regression analysis revealed a K-line tilt of <6.11 degrees as a risk factor for effective conservative single-segment CSR treatment (P<0.05). The 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 degrees) as a potential predictive indicator for conservative single-segment CSR management effectiveness. The measurement of K-line tilt provides essential information for clinicians to formulate treatment strategies for single-segment CSR.