SIB# 362 Pelvic Incidence Can Be Changed by Posture During Imaging.

The Study: Pelvic Incidence Can Be Changed not only by Age and Sex, but also by Posture Used during Imaging.

The Facts:

a. They compared the measurement of pelvic parameters found on CT scans and x-rays.

b. The x-rays were taken with the patients in a standing position while in the CTs the subjects were in the supine position.

c. They had 254 subjects.

d. The mean age of the subjects was 61.3 years of age.

e. “When measured using CT compared to X-ray, SS [sacral slope] increased by 3.5°, PT [pelvic tilt] decreased by 6.7°, and PI [pelvic incidence] decreased by 3.2°.”

Take Home:

There is a difference in the measurements taken from supine CT scans and standing radiographs.

Reviewer's Comments:

I think that most of us expected there to be a difference in these types of measurements taken supine as opposed to standing. In this case we use two different technologies which is a bit like comparing apples and oranges. But it is always good to have a study to look at something as there are often unexpected results.

Reviewer: Roger Coleman DC

 Editor: Mark R. Payne DC

 Reference: Moon JW, Shinn JK, Ryu D, Oh SY, Shim YS, Yoon SH. Pelvic Incidence Can Be Changed not only by Age and Sex, but also by Posture Used during Imaging. Korean J Spine 2017 Sep;14(3):77-83. doi: 10.14245/kjs.2017.14.3.77. Epub 2017 Sep 30.

 Link to Abstract: https://www.ncbi.nlm.nih.gov/pubmed/29017301