Goal of the Study?
Intradiscal vacuum phenomenon is a commonly observed radiological finding in the spine but not much is known about its pathophysiology. A recent paper was published in The European Spine Journal1 and sought to explore more about this curious phenomenon by looking at patients with it and to see if the anatomical findings could reveal something dynamic about the spine.
Why are they doing this study?
The main purpose of the study is to learn more about what may cause a vacuum phenomenon and what it may mean from a diagnostic and therapeutic perspective. The most popular theories about why it forms include the presence of negative pressure. These researchers wondered if it could relate to spinal instability.
What was done?
Seven hundred and twenty-one patients with chronic low back pain were investigated using flexion-extension x-rays along with MRI. Measurements of the x-rays looked at sagittal translation and angulation, lateral listhesis and disc collapse. They also took into account disc height and graded the images for degeneration using Pfirrmann’s grading scale.
What did they find?
Interestingly, and not too surprising, the researchers found vacuum phenomenon in over half of the chronic low back pain patients along with an increase in age compared to controls. Disc height loss, side-to-side translation (coronal listhesis), forward back-and-forth translation (sagittal angular motion), and greater disc degeneration were all found to be more present with vacuum phenomenon.
Why do these findings matter?
Prior to this research, radiologists and the professionals they share their findings with often thought of the vacuum phenomenon as an ‘incidental finding’. Now, this new research can help inform the professional about the dynamics of the spine which in turn, can help target appropriate treatment stability strategies. These findings also fall in line with other research that looked at ‘cavitation’ using a model conducted by Jerome CJ Fryer BSc DC authored in PLOS One2 and also in the Journal of the Canadian Chiropractic Association3. In other words, when gas is seen within a joint space (whether synovial or intradiscal), inference should be made about the laxity of the joint complex as a whole.
“When one sees a vacuum phenomenon, one’s first suspicion should be hypermobility. This can help carve out a therapeutic path to reducing low back pain if present.” Jerome Fryer DC
- Advanced disc degeneration, biplanar instability and pathways of peri-discal gas suffusion contribute to pathogenesis of intradiscal vacuum phenomenon ↩
- Real-Time Visualization of Joint Cracking ↩
- A proposed in vitro model for investigating the mechanisms of ‘joint cracking’: a short report of preliminary techniques and observations ↩