Is extracorporeal shockwave (ESWT) missing from your toolbox when you treat disc herniations?
If your practice is like mine, you get several patients a day with disc herniations. Before the 1990s, the only tool we had to address disc herniations was the chiropractic adjustment. Several decades later, considerable advancements in technology allow DCs to address intervertebral disc (IVD) pathology. A review of these tools would include chiropractic adjustments, spinal decompression therapy, therapeutic exercises and Class IV laser therapy. There may be more on this list, but these are generally accepted tools our profession uses.
In my 25 years of practice, I have noticed the best outcomes result from carefully examining the patient to determine the exact nature and cause of their symptoms. Once you understand the nature and cause of the patient’s condition, you consider the tools available and their physiological effects, and match the patient’s condition to the desired effect. As you know, no two patients are the same.
Often, we get patients in our office who present with an MRI that clearly demonstrates a lumbar disc herniation. However, during the physical exam you notice most of the patient’s symptoms can be traced to a sacroiliac joint dysfunction. This patient’s treatment will probably be much different from treatment of an individual who presents with a disc herniation on their MRI and demonstrates during the physical exam clear signs of nerve root compression down the leg. The tools you end up using and the way you use them will be determined by the patient’s condition.
A fairly new tool has shown up that represents a considerable advancement in the way we can address disc pathology. Much of this improvement was showcased in a recent article in Spine Journal, “Low energy extracorporeal shock wave therapy combined with low tension traction can better reshape the microenvironment and degenerated intervertebral disc regeneration and repair.”1 If you are like me and have a practice that treats several disc herniation patients a day, just the title of this article was enough to get you excited. In my opinion, this article should be required reading for anyone who treats disc herniations in their practice. Its introduction provides a fascinating overview of the pathophysiology of disc herniations and why they have been so pervasive.
Here are some key points with my comments:
The IVD is a biomechanical structure composed of many interacting and related tissues. It is the largest avascular and non-innervated tissue in the body. The supply of nutrients and transport metabolites is principally via the exchange of the endplate in the form of molecular dispersion fluid, which also results in the internal environment being inevitably affected by the nutritional environment, mechanical distribution, cytokines and components of the extracellular matrix. The key takeaway is that the disc is largely avascular and non-innervated, entirely reliant on the vertebral endplate for its supply of nutrients. Thus, if you have unhealthy endplates you are unlikely to improve the disc’s condition.
Previous studies have shown that for disc regeneration or repair to occur, a certain number of functional cells, a stable mechanical environment and adequate nutrition are essential. Although bone marrow mesenchymal stem cells have been successfully implanted into degenerated discs, their full potential may not be realized if unsuitable conditions of the degenerated disc remain. There have been several attempts to introduce stem cells into degenerated discs. However, the attempts fail because the condition of the vertebral endplate does not permit adequate nutrition of the stem cells, making treatment ineffective.
In clinical practice, it is difficult to distinguish the integrity of an endplate using conventional MRI. This is why the endplates, especially the bony endplates, are often overlooked and their role underestimated when diagnosing IVD degeneration.
When to review patients’ MRIs for disc herniations
If you are not evaluating the endplates, you do not have a complete understanding of discs’ condition. The science clearly shows that without a healthy endplate you cannot have a healthy disc. Another reason we need plain film X-rays of patients is that we must evaluate sclerosis and integrity of the bony endplates.
Nutritional issues in transport disorders are key factors that affect IVD regeneration and repair. For the majority of moderate and severe IVD problems, the cartilaginous endplate is often calcified, sclerotic or ossified. With the narrowing of their intervertebral space, bony endplate lesions such as Schmorl’s nodes, sclerosis, ossification and even collapse and fracture can occur. This could result in decreased permeability, which hinders the exchange of nutrients and metabolites in the disc. Nutrient flow is a key contributor to IVD regeneration.
We have previously demonstrated that low-tension traction is more effective than high-tension traction in restoration of the height and rehydration of a degenerated disc, and to some extent reconstruction of the bony endplate, which better reshapes the microenvironment for disc regeneration and repair. Is this your understanding of how decompression works? Are you using low-tension or high-tension traction on your patients? If you use too much pressure you are not using the best practice supported by science. Are you telling patients you are decreasing the pressure inside the disc, pulling the nucleus back in? Or are you telling them you are reconditioning the vertebral endplate, which is the real target if you are trying to improve a disc herniation?
Recently in the field of musculoskeletal medicine, the use of ESWT to stimulate tissue repair and regeneration has been increasingly studied, and progress has been achieved, although the specific mechanism remains unclear. Using ESWT to treat osteoarthritis can significantly promote the proliferation of chondrocytes, effectively preventing the degenerative cascade of cartilage and subchondral bone, and to some extent delaying the development of osteoarthritis. The pathological changes of osteoarthritis, caused by the degeneration of cartilage and subchondral bone, are very similar to those of degenerative disc disorders, which are closely related to bony endplate degeneration. If you have been keeping up with the science of shockwave therapy, you know several studies have demonstrated improvement of osteoarthritis when the subchondral bone is treated. Since there are similarities between subchondral bone and vertebral endplates, the following study seeks to test the theory that IVDs can be regenerated when shockwaves are applied to the bony endplate alongside low-tension traction.2
Study results
The subjects in this study are rats, divided into several control groups, including a low-tension traction-only group, a shockwave-only group and a group that received low-tension traction combined with shockwave. The study’s authors conducted several analyses of the disc and endplate tissue, including disc height measurements and magnetic resonance analysis measurement of glucosamine glycan content, histological analysis, gene expression, evaluation of the bony endplate, atomic force microscopy imaging and nanochemical testing. Here is a brief synopsis of their findings:
Shockwave therapy combined with low-tension traction can better reconstruct the bony endplate and facilitate opening of the nutrient channels. Thickening or hardening of the subchondral bone or vertebral endplates can diminish the flow of nutrients into the disc. Once nutrient flow has been reduced or interrupted, regeneration of IVDs is unlikely.
Low-energy ESWT combined with low-tension traction reduced annulus fibrosus ring tension and nucleus pulposus stress, remodeling the disc’s biomechanical microenvironment. Keep in mind, we are dealing with fibroblasts and all the cells derived from fibroblasts. These include chondrocytes and osteocytes, among other cells. These cells are very sensitive to their environment and will physically change as a result of stress. The authors have shown that tissue can be remodeled and healed with the application of low-tension traction and shockwave together.
Low-tension traction in combination with ESWT promoted regeneration of the IVDs by inhibiting extracellular matrix degradation and maintaining nucleus pulposus cell activity. Without getting into too much of the biochemistry, let me explain: Once oxygen is diminished inside the IVD, the cells start to die and thus produce enzymes that break down the extracellular matrix of the IVD. The only thing that can stop this is fresh nutrients and enzymes that inhibit breakdown of the extracellular matrix proteins that make up a majority of the disc tissue. This is another reason you need to focus on the vertebral endplate and not just the disc itself.
What this means to you and your practice
First, the implications of a tool that can break up sclerosis and revascularize degenerative tissue are enormous. I want you to sit and think of all the lives you could change with just that capability!
Successful treatment of IVD disorders is not as simple as just placing a patient on a decompression table and hitting the go button; there are many factors to consider. In my opinion, an overreaching concern is the health and integrity of the adjacent vertebral endplates. These endplates are very sensitive structures and when they lose their vascularity, they lose the ability to maintain the integrity of the IVDs. Providing space to the disc is only half the battle. Restoring nutrient flow to the disc is of equal or even higher priority when you rehabilitate these patients. Rehabilitating the endplates is of utmost importance to restoring nutrient flow. Up until now, no definitive tool could successfully restore vascularity to subchondral bone and endplate tissue.
Final thoughts
Numerous studies show ESWT can address subchondral sclerosis and restore vascularity to tissue. Keep in mind, it’s not as easy as simply buying the machine and putting it on the patient. You must consider many factors and develop a level of competency to make this therapy work, and you have several devices to choose from. In my opinion, the more focused the shockwave, the more certain you can be about where the therapy is directed and that adequate energy is reaching its intended target. My advice is to get adequate training in both low-tension traction and ESWT. Both tools can be great assets to you and your patients when used properly. Try buying from a company committed to supplying the tools and training to help you succeed. Also, if you are not familiar with the pathophysiology of vertebral endplates as they relate to disc herniation, it’s time to do some reading.
PETER J. BROCKMAN, DC, a native of Los Angeles, California, received his undergraduate training in microbiology at the University of South Florida, finishing with a bachelor of science degree. He then received his doctor of chiropractic degree from Cleveland Chiropractic College Los Angeles; he is also board-certified in acupuncture. Brockman has been in private practice since 1999 and is currently the clinic director and owner of South Lake Wellness and Injury Center PL. He is an instructor for KDT Decompression Systems/Technique, as he enjoys giving back to the chiropractic profession.
References
- Che Y-J, et al. Low energy extracorporeal shock wave therapy combined with low-tension traction can better reshape the microenvironment in degenerated intervertebral disc regeneration and repair. Spine J. 2021;21(1):160−177. PubMed. https://pubmed.ncbi.nlm.nih.gov/32800896/. Accessed August 25, 2024.
- Guo JB, et al. Stable mechanical environments created by a low-tension traction device is beneficial for the regeneration and repair of degenerated intervertebral discs. Spine J. 2020;20(9):1503-1516.
https://www.thespinejournalonline.com/article/S1529-9430(20)30140-6/abstract#articleInformation. Accessed August 25, 2024.