Dynamic Disc Designs
three dimensional modelling

Three-dimensional Modelling Dynamic Diurnal Disc Changes – Posterior and Anterior Look with MRI

Goal of the Study?

We all know that LBP is a worldwide problem. Yet, the disc and its functional relationship to low back pain are poorly understood. These researchers worked to use MRI and three-dimensional modelling to measure in-vivo shape changes of intervertebral discs over the dynamic diurnal cycle1. They set out to create a framework of disc shape changes for a better understanding of the underlying structure changes and the associated functional disruptions.


Why are they doing this study?

The main purpose of the study is to learn more about the spatial variations seen in disc shape over the day/night cycle and to evaluate the inter and intra-rater reliability using MRI and three-dimensional modelling of the L5-1 motion segment.


What was done?

Eight young healthy volunteers were imaged at 7 am, after resting supine for 45 minutes, and thereafter, to return at 3:30 pm for a second MRI. The time between scans was approximately 7 and a ¼ hrs. Three-dimensional modelling was constructed from the MRI scans. 


What did they find?

The researchers validated a protocol to measure shape changes of the L5-1 disc using MRI and solid modelling with good inter and intra reliability. What they found was that disc height loss was most notable in the posterior region of the intervertebral disc. They found a disc height loss of 13% posteriorly while anteriorly only a 5% change was noted. The authors made a point that most disc-related pathology is found posteriorly in the form of annular fissures, disc bulges, disc protrusion and disc extrusions.



Why do these findings matter?

Learning the dynamics of the discs can help create a clinical framework when piecing together a patient’s history and the diurnal onset of the triggers. Lower back symptoms that originate further along in the day, could likely point those attending (chiropractors, physicians, physiotherapists, pain interventionalists) with a probable pathoanatomical source of a patient’s low back pain. If lower back pain tends to increase as the day goes on, one must think about the dynamic diurnal disc height loss and the associated anatomical structures that may be involved. Teaching a patient through effective dynamic disc modelling can help in the management of their pain. Recumbency is a powerful tool when used in the right way.


At Dynamic Disc Designs, basic science is at our core. We believe the diurnal changes in the disc are often underappreciated as it relates to a person’s spine symptoms. Teaching the basics of height change dynamics can help in the decision-making surrounding back pain.