The Morphometry of the Cervical Vertebral Column in the Sagittal Plane: Comparing Methods for Determining Cervical Lordosis Angle

Background: The aims of this study were to: (i) to analyze the morphometric characteristics of the cervical vertebral column in the sagittal plane; and (ii) compare morphometric methods used for determinating cervical lordosis angle. Materials and Methods: Direct cervical sagittal radiographs of 175 adults were analyzed and cervical lordosis angle was evaluated by Cobb (C2-C7), central cervical lordosis angle, posterior tangent, and Risser & Ferguson methods. In addition, occipitocervical angle (occiput-C2) and cervical vertical tranlation distance were deter-mined to assess upper cervical lordosis and forward head posture, respectively. Results: The measured cervical lordosis angles were differed (p<0.05) depending on the measurement met-hod. There was a strong negative correlation between cervical lordosis angle and occipitocervical angle (r = -0.707), a weak negative correlation between cervical lordosis angle and cervical vertical translation distance (r = -0.253) and a moderate positive correlation between occipitocervical angle and cervical vertical translation distance (r = 0.552). It was observed that an increase of 1 mm in the cervical vertical translation distance cau-sed an increase in the occipitocervical angle about 0.6 degrees. Conclusions: In planning cervical surgery, the balance and alignment of the cervical vertebral column in the sagittal plane should be evaluated in detail. The contour of the cervical vertebral column in the sagittal plane and the limits of cervical lordosis angle are important in the evaluation of cervical pathologies. The obsserva-tions from this study will benefit the understanding of vertebral column morphometry will contribute to the literature in anatomy, physiotherapy, radiology, and cervical regional surgery. Key Words: Cervical lordosis angle, cervical vertebrae, morphometry, radiography, sagittal plane