Introduction: A scoliometer, also know as an inclinometer or level, is a non‐invasive and easily applied clinical tool used to measure trunk asymmetry. The most accurate measurement of vertebral rotation is by CT axial imaging. However, concerns exist over the radiation exposure associated with computed tomography. There is a desire to objectively assess the amount of vertebral body derotation correction following surgery for AIS. Research on the efficacy of various surgical derotation maneuvers has used the scoliometer as a way to quantify results without verifying the accuracy of the scoliometer by comparing it to the “gold standard” of CT imaging. This report looks at the mathematical correlation between the two measurements.
Methods: A retrospective review of 29 patients with AIS was performed. Apical trunk rotation as measured by a scoliometer was obtained in a prospective manner. Rotation of the apical lumbar and thoracic vertebrae were measured on pre‐operative CT scan. Statistical correlation analysis between the two measurements was performed.
Results: A statistically significant correlation between vertebral rotation as measured on CT scan and scoliometer could not be established. The Pearson's product moment correlation coefficient for the thoracic curves was 0.266. For lumbar curves, the Pearson's product moment correlation coefficient was ‐0.388. Neither of these correlations was statistically significant (p>0.05).
Conclusion: There was no statistically significant correlation between vertebral rotation as measured on CT scan and trunk rotation as measured by scoliometer. Vertebral body rotation is only one factor that contributes to side‐to‐side trunk asymmetry. Other factors that influence trunk shape may include adipose tissue coverage of bony structures, differences in rib morphology, and muscle mass asymmetry.
Significance: A scoliometer cannot be used as an alternative to axial CT scans for measurement of vertebral rotation.