low rate loading of intervertebral disc

Low rate loading of intervertebral disc disease

Low rate loading of intervertebral disc disease (IVD) demonstrated enhanced net transport into the intervertebral disc In Vivo in a recent study published in The Spine Journal.

 

These authors examined low-rate loading (0.5hz ) of rabbit subjects and measured the uptake of gadodiamide. They found that low-rate loading improved lumbar disc clearance from the nucleus compared to the unloaded subjects’ discs.

 

Introduction

The intervertebral disc is an important component of the spine, acting as a cushion between the bones. This disc relies on blood vessels in nearby tissues for nutrients and waste expulsion. Disc degeneration can result when the transport system between the disc and the blood vessels in the nearby tissues is damaged. The main methods of transportation are diffusion and convection, which can be hindered by the calcification of certain tissues or decreased levels of certain proteins.

Studies show that activities like exercise can move nutrients into the intervertebral disc. Yet, other studies are saying that fluid flow doesn’t play as big of a role as suspected. Upon doing more studies with radioactive tracers in animals, scientists have discovered that it is not just about how much nutrients are present for the intervertebral disc at specific moments but also how nutrients move in and out over time. Understanding nutrient supply with time in context could be the key to solving s greater percentage of lower back pain.

 

Disc Degeneration Model

Experimentation and Analysis

For the experimentation phase in investigating how the spine responds to different degrees of loading, 13 rabbits were used as primary subjects. Their spines were implanted with pins and posts for the application of controlled pressure. The Rabbits’ spines were loaded for different durations, and MRI scans were run so that they could observe how molecules within the spine moved when loaded. By comparing these measurements for various durations, scientists hoped that their understanding of how the spine responds to different loading durations would help them gain insights into how physical activity affects spine health. Thereby enabling them to develop better treatments for spine-related human problems.

 

The study found that when the spine experienced gentle, slow pressure, a substance called gadodiamide was quickly taken up and removed from the central part of the spinal disc, known as the nucleus pulposus. However, in nearby areas where there was no pressure, gadodiamide was absorbed at a slower rate, and it wasn’t cleared away during the 20-minute period. After 5 and 10 minutes of gentle pressure, the uptake of gadodiamide into the nucleus was significantly increased compared to areas without pressure, but there was no significant difference at the 15-minute mark. Interestingly, the pressure did not significantly affect the transport in the outer parts of the disc or the cartilage endplate. However, there were differences between the upper and lower parts of the endplate. All in all, there were no notable differences in bone density between areas with pressure and those without.

 

Research Findings and Postulation for Improved Spinal Health

The study showed that when the spine undergoes gentle slow pressure, it facilitates the uptake and clearance of small molecules in the intervertebral disc. Initially, the concentration of the substance used to track transport increased in the nucleus pulposus. Still, as pressure continued, the concentration of this substance (Gadodiamide) dropped as fluid flow cleared it from the disc. This slow, gentle disc pressure causes disc deformation. However, this is observed more in the nucleus and less in other parts of the disc.

These findings suggest that gentle pressure, applied at a low rate, has potential benefits for disc health. It aids nutrient supply to discs, consequently slowing or reversing disc degeneration. Incorporating low-rate and gentle loading into physical therapy could promote overall spinal health. Lifestyle changes like regularly visiting the gym, where individuals can undergo supervised weightlifting of appropriate weight sets, can also be beneficial for alleviating back pain and improving back health.

Dynamic Disc Designs Corp. applauds the authors for this publication. Mechano factors in understanding the regenerative potential of degenerated discs are an important field to continue researching. Understanding the basic anatomical science of biorheology in and around the intervertebral discs will lead to better manual treatment strategies in the future.

These authors provided an important puzzle revealing the frequencies discs best respond to. Mimicking the natural biomechanical forces that discs experience in the human body, such as blood pressure (which is 1.33Hz at approx. 80 beats per minute) and breathing (which is 0.25Hz at 18 breaths per minute), should provide ongoing clues as to the optimal bio-frequencies that will provide the most promise in regeneration.