J Korean Neurosurg Soc.  2023 Nov;66(6):611-617. 10.3340/jkns.2023.0146.

The Sagittal Balance of Cervical Spine : Comprehensive Review of Recent Update

• Lee SH
• Kim TH
• Kim SW
• Rim HT
• Lee HS
• Kim JH
• Chang IB
• Song JH
• Hong YK
• Oh JK

• KMID: 2547455
• DOI: http://doi.org/10.3340/jkns.2023.0146

Abstract

The cervical spine plays a critical role in supporting the skull, maintaining horizontal gaze, and facilitating walking. Its unique characteristics, including the widest range of motion among spinal segments, have led to extensive research on cervical sagittal alignment. Various parameters have been proposed to evaluate cervical alignment, with studies investigating their clinical significance, correlation with symptoms, and implications for surgical interventions. Recent findings suggest that cervical sagittal alignment not only impacts the cervical spine but also influences global spine-pelvic alignment through compensatory mechanisms. This comprehensive review examines classical and new parameters of cervical sagittal alignment and considers the dynamic and muscular factors associated with it.

Keyword

Cervical spine; Cervical sagittal alignment; Cervical spine parameter; Cervical spine deformity

Figure

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  Fig. 1. Cervical lordosis measurement methods. A : Modified Cobb method. The angle between lines drawn perpendicular to inferior endplates of C2 and C7. B : Jackson physiological stress lines. The angle between lines parallel to the posterior surfaces of the C2 and C7 vertebral bodies. C : Harrison's posterior tangent method, the sum of the angles for the overall cervical curvature is measured by lines parallel to the posterior surfaces of all cervical vertebral bodies from C2 to C7.

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  Fig. 2. Comparison between TIA and PI. Greater TIA or T1S requires more CL, as greater PI requires more lumbar lordosis. TIA : thoracic inlet angle, NT : neck tilt, T1S : T1 slope, PI : pelvic incidence, PT : pelvic tilt, SS : sacral slope.

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  Fig. 3. C2-7 SVA is distance between C2 plumb line and posterior, superior endplate of C7 body. SVA : sagittal vertical axis.

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  Fig. 4. K-line tilt is the angle between line connecting the midpoints of the spinal canal at C2 and C7 and a vertical line.

Reference

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