Written by D. Reese Hand, DVM
Shock wave therapy or ESWT (extracorporeal shock wave therapy) is a non-invasive treatment that can be used as a regenerative therapy to facilitate healing.
The therapy, adapted from the technology to break up kidney stones (a procedure called lithotripsy), has been used in veterinary medicine for well over a decade. ESWT causes blood flow to increase as well as growth factor stimulation which is used to assist in healing. Inflammation is decreased as well as pain to encourage healing.
ESWT uses energy waves that are transmitted through the skin into deeper anatomical structures. When people hear ‘shock’ they associate it with electrical shock, but it’s actually a physics term used to describe a high energy impulse or sound wave (like the sound of a gun firing or thunder). The waves are generated in a fluid medium inside a transducer head and are focused at the desired treatment area.
Are there different types of shock wave?
There are three types of shock wave devices used in veterinary medicine. They are broken down into: Electrohydraulic – highest energy waves with the largest focal area to better treat large areas (tendons, joints, and backs). These are the most common used in equine therapy. Energy level and depth of penetration are variable to suit treatment site.
Electromagnetic – produces lower energy with a smaller focal area. This was designed to better focus on small targets like a kidney stone without affecting the surrounding tissue, but is also marketed for orthopedic indications in horses. Pizeoelectric-produces a mechanical vibration of a crystal that has the smallest energy wave.
While technically not a shock wave, radial pressure devices have also been marketed as shock wave devices in veterinary medicine. These machines work like a small jack hammer to transmit mechanical energy to the body. These devices have much lower energy and extremely limited penetration relative to true shock wave devices.
What can shock wave do?
It has been clinically proven to stimulate new bone growth, release growth factors, stimulate stem cells in the animal’s body, increase blood flow and new vessels and stimulate cells to generate new connective tissue.
What are the common uses of shock wave in horses?
Its use has been successful in both acute and chronic conditions involving bone and soft tissue.
What equine conditions are treated using shock wave therapy?
Shock wave therapy is used to treat suspensory strains and tears both in the body and the branches. It is also used for tendon tears involving the deep flexor and superficial flexor tendons and arthritis involving any joint like ringbone, collateral ligament injuries and navicular syndrome. Neck and back pain (kissing spines) have shown tremendous improvement if not resolution. Muscle tears and wound management are significantly reduced. ESWT has anecdotal improvement with use in osteochondrosis such as bone cysts.
In summary, it’s important to use a shock wave machine that provides a focused beam with a large focal area. The machine needs to have deep penetration but needs to be variable (0-110mm of penetration). Energy needs to be variable to treat the variable lesions that are seen in equine injuries. Treatments are usually done 10-14 days apart and routinely only require light sedation and take only a few minutes. The average number of treatments is 3-4, but can vary depending on the injury and its location.
Equine Sports Medicine and Surgery and Dr. Reese Hand have been offering VersaTron shock wave therapy since 2002. To find a vet in your area who offers shock wave therapy, please use our vet locator at http://www.pulsevet.com/find-a-vet/.
D. Reese Hand, DVM
Diplomate American College of Veterinary Surgeons
Equine Sports Medicine and Surgery