The Invention and Early Uses of Shockwaves
The invention of shockwaves dates to the late 20th century when German researchers developed this technology. It was initially used for lithotripsy which is a noninvasive method for breaking kidney stones. The first successful application of this method occurred in 1980.
This enticed research into other medical uses. The second area was in cardiology.
Expansion of Shockwave Therapy Applications
These successes expanded the use of extracorporeal shockwave therapy into other areas such as musculoskeletal injuries, soft tissue injuries, and chronic wound healing. As the machines became more available, and cost was decreased, outpatient application became commonplace, offering unique therapeutic non-surgical treatment modalities for common conditions.
In orthopedics, difficult conditions responded to shockwave therapy such as chronic plantar fasciitis, tendinopathies, and nonunion fractures. Subsequent technological advancements in the machine itself broadened the therapeutic scope as they became available for outpatient use in the office setting.
Mechanism of Action
Shockwaves are acoustic waves characterized by high peak pressure, rapid rise and fall, and very short duration. The waves easily propagate through tissue, inducing cavitation and stress at the target. This action stimulates a biological response by the body including:
- Reduction and or elimination of calcifications
- Stimulation of repair including collagen synthesis
- Enhances angiogenesis and neovascularization
- Increases cellular metabolism and activation of mesenchymal stem cells
The action of shockwave stimulates the pathways of proliferation, migration, and subsequent differentiation. Inflammatory mediators can be stimulated or reduced. This action will be explained further in this article. Pain is reduced via neuronal inhibition and disruption of the pain cycle.
Cavitation microbubbles can enhance perfusion and nutrient access to damaged tissues.
How are Shockwaves Generated?
Shockwaves are generated depending on the type of device used for the treatment.
Radial Shockwaves
Radial shockwaves are generated electromagnetically or pneumatically. Pneumatic systems utilize compressed air to accelerate a projectile in a tube. When the projectile strikes a metal applicator at the tube’s end, a radial wave is generated. This wave projects outward. Electromagnetic systems use an oscillating coil to create waves.
Radial waves diverge from the generation point into the target.
Radial shockwaves are well suited for superficial tissue conditions. The lower energy dispersion makes them an excellent choice for conditions where broader energy is needed in larger fields such as plantar fasciitis, lateral and medial epicondylitis, and multiple trigger points. These devices are lower cost, portable, and require little training for operation.
Focused Shockwaves
Focused shockwaves are generated by one of three mechanisms:
- Electromagnetic coil creates a magnetic field that deforms a membrane and forms a shockwave.
- Electrohydraulic waves where high voltage electrical energy produces a spark in fluid creating shockwaves that are directed using a reflection device.
- Piezoelectric generation where crystals are activated simultaneously creating waves that converge at a focal point.
Focused shockwaves are suitable for deeper tissues, bones, and calcifications such as nonunion fractures, deep tendon treatments, and calcific conditions. They are more expensive, approximately 9 to 10 times the cost of the radial device.
Comparison Between Radial and Focused Shockwaves
In comparison, the radial energy is low to medium, with a divergent waveform and lower cost. It is excellent for surface and mildly deeper applications. The focused energy is low to high, with a convergent waveform at a significantly higher price point. It is excellent for deep tissue and calcific tissue applications.
Study: Immune Modulation and Osteoarthritis
A recently published study compared the inflammatory and anti-inflammatory effects of shockwave treatment on arthritic conditions in the elderly and concluded with surprising results.
The Effects of High and Low Dose Extracorporeal Shockwave Therapy on Immune Activation and Immunosuppressive Markers in Elderly Patients with Osteoarthritis: A Study Protocol for a Randomized Controlled Trial
Am J Clin Exp Immunol 2023 Dec 15;12(6):164-172 PMID 38187367
Objective: This randomized controlled trial aims to compare the effects of high versus low dose extracorporeal shockwave therapy on immune system activation and regulation in elderly patients with osteoarthritis.
Chronic low-grade inflammation and immune system dysfunction are integral to the pathogenesis and progression of OA. Increased pro-inflammatory cytokines such as interleukin IL-1B, IL-6 and tumor necrosis factor (TNF) stimulate cartilage catabolism and joint deterioration. Activated innate cells including macrophages, mast cells and neutrophils infiltrate the synovium and further potentiate inflammation. These immunological changes promote OA symptoms and structural damage.
Due to the limited research on shockwaves for OA and associated immune changes specifically in the elderly population, this study was instituted. This study aimed to address the gap about immunological consideration on shockwave efficacy by investigating the immunomodulatory effects of different shockwave dosing regimens in geriatric populations with OA of the knee.
This study demonstrated that high dose extracorporeal shockwave treatments significantly increased inflammatory cytokines and decreased anti-inflammatory regulatory cells compared to low dose ESWT in the elderly. Over the four weeks of the study, with four treatments, the high dose protocol will cause elevated interleukin IL-!b, IL-6 and TNF. This represents a heightened immune system. In contrast, the low dose regimen will maintain Treg levels that are associated with protective immunosuppression. These results provide evidence that shockwave induces dose-dependent immunomodulation in the elderly with higher intensities causing pro-inflammatory effects.
Higher intensities exceed mechanical signals for beneficial tissue remodeling and induces subsequent excessive catabolism. However, both groups demonstrate symptomatic relief from the baseline consistent with the recognized analgesic effects of shockwaves.
The proposed mechanism of high dose shockwave treatment inflammatory etiology is the cell membranes are hyperpolarized, activating calcium channels that trigger inflammatory cascades. In contrast, low dose shockwaves polarize macrophages towards the M2 or anti-inflammatory phenotypes.
Conclusion of this study about advancing age involves heightened baseline inflammation and immune dysfunction. Intense ESWT regimens theoretically accelerate joint deterioration by amplification catabolic cytokines and oxidative stress. Conversely, low intensity shockwave therapy help counteract chronic inflammation and augment regenerative signaling.
This study has important implications regarding ESWT protocols for musculoskeletal disorders in the elderly population. Applying high dose shockwaves in this group may tip the balance toward excessive catabolism, immune activation and tissue damage. Lower dose shockwaves are optimal in this population to harness the anti-inflammatory and regenerative therapeutic capabilities while avoiding the stimulation of the already heightened immune system.
Focused vs. Radial Shockwave Therapy for Knee Osteoarthritis
Comparative Effectiveness of Focused Extracorporeal versus Radial Extracorporeal Shockwave Therapy for Knee Osteoarthritis- Randomized Controlled Study
Int J Environ Public Health 2022 Jul 24;19(15):9001 PMID 35897371
Purpose: To compare focused extracorporeal shockwave and radial shockwave therapy for symptoms in patients with osteoarthritis of the knee.
Conclusion: At the end of 4 weeks, the VAS score was substantially reduced in both groups with a greater reduction in the focused group. Both groups, showed significant improvement in the VAS score, WOMAC score and 6 minute walk test. Our results showed that the focuses ESWT was more effective, but both showed significant improvement for the symptoms of OA knee.
The Efficacy of Extracorporeal Shock Wave Therapy for Knee Osteoarthritis: An Umbrella Review
Int J Surg 2024 Apr 1;110(4):2389-2395 PMID 38668665
Background: An umbrella review was conducted to compare the effectiveness of extracorporeal shockwave therapy versus non-ESWT in the treatment of knee osteoarthritis.
Conclusion: Based on the results of our analysis, ESWT is now an effective therapy for improving pain and function in patients with osteoarthritis of the knee.
Juventix’s PhysioPRO Shockwave System
Juventix Regenerative Medical is an industry leader in the regenerative medical field. Juventix is pleased to announce the addition of the PhysioPRO Shockwave System to the vast array of products and services available to the regenerative professional. This FDA registered radial shockwave device is a clinical grade system that induces intracellular and extracellular reactions in tissue to stimulate the regenerative cascade. The cells are activated forming new cells in damaged tissues, accelerated blood flow is stimulated to provide increased nutrients and angiogenesis is restored.
Multiple treatment protocols are built into the programming of the machine creating a simplistic device that is extremely user friendly. The PhysioPRO is not only for musculoskeletal problems but can also be advantageous in aesthetic treatments such as stubborn areas in fat reduction.
The simplicity of use, the low cost of operation and acquisition make the PhysioPRO a welcome addition to any medical, aesthetic or rehabilitation practice.
RESTORE, REVIVE, REGENERATE- JUVENTIX REGENERATIVE MEDICAL
Regenerative Regards,
Dr. Robert McGrath
