Goal of the Study?
The regenerative potential of a degenerated disc has been questioned over the years. In this ISSLS prize-winning study1, these researchers looked at a particular low load rate, a special rate they have been investigating for years. Discs have a propensity to degenerate, likely due to their avascularity and nutrient supply routes, but this biomechanical study on the mechanobiology of the disc demonstrated regenerative promise. In this animal model, a low load rate of 0.5Hz (cycle of compression and decompression every 2 seconds) regenerated discs that were experimentally degenerated. You’ll want to see the results.
Why are they doing this study?
In 2021, a group of researchers presented the regenerative potential of degenerated intervertebral discs on a low rate load cycle. (Cyclic loading enhances small molecule transport in the 8-week degenerated rabbit intervertebral disc. In: Annual meeting of the orthopedic research society. Orthopaedic Research Society, Virtual.) Capogna E, Walrath E, Brown E, Furst W, Glennon J, and Ledet E have been looking at an animal model to see if they can induce regeneration of a degenerated intervertebral disc in a non-pharmacologic and non-invasive way. They have been exploring the role of convection in disc nutrient transport in an animal model.
What was done in this study?
Fifty-six female New Zealand White rabbits were used in this study. With all animals greater than 12 months old, they were randomly assigned into:
- Control group
- Eight-week degeneration group
- Eight-week degeneration group followed by eight-weeks of therapy group
A 16 gauge needle was inserted into the L4-5 disc to induce degeneration. This is a common technique used by researchers called disc puncture, which has shown repeatability of inducing degeneration in animal models demonstrating degeneration at two-week post puncture and gradual increase of the degenerative state over a 24-week period.
In the third group, therapy started at the 8-week post-puncture and was placed in a custom in vivo loading apparatus that controlled the axial load movement at the L4-5 disc. Loads of approximately four times body weight (220 N) were applied cyclically in compression and back to neutral (decompression) at 2-second intervals. The animals underwent continuous loading for 2 hrs a day for five days per week for eight weeks.
An investigation done by microscopy and CT was performed.
What did they find?
Low rate cyclic loading at 2-second intervals demonstrated regeneration in the degenerated induced group.
Why do these findings matter?
Degenerated discs often contribute to lower back pain. Importantly, if this work could be extrapolated to humans, then a non-invasive, non-pharmacological therapy could offer a simple strategy for this global problem. In this study, 8 weeks of cyclic loading, for 2 hrs a day 5 days a week, demonstrated a direct mechanobiological response to regenerating intervertebral discs.
At Dynamic Disc Designs, we create dynamic human anatomy models to help reveal the spinal structures that matter in the case of lower back teaching. Often it is difficult for patients to understand the complexities of the anatomy and their respective dynamic symptoms. We assist the professionals in their pursuit to educate the people they care for.