Pavlov, Torg and others developed a ratio based on measurements of the vertebral bodies from the lateral neck radiographs. This can help identify patients with relative cervical spine stenosis.
Cervical vertebrae evaluated (4 or 5): C-3 to C-6 or C-7
Measurements:
(1) anterior to posterior (sagittal) diameter of the vertebral body at its vertical midpoint in cm
(2) anterior to posterior diameter of the cervical canal (from the posterior edge of the vertebral body at its vertical midpoint to the spinolaminar line) in cm
where:
• The measurements need to be taken consistently and perpendicular to the reference points.
ratio =
= (ratio of cervical canal) / (ratio of vertebral body)
Interpretation:
• The ratio is normally > 0.8.
• In patients with relative cervical cord stenosis with neuropraxia 1 or more vertebral bodies showed a ratio <= 0.8 (sensitivity reported by Torg et al 1993 as 100%).
• A control population without symptoms had 4% with a ratio <= 0.8.
To read more or access our algorithms and calculators, please log in or register.
