Extracorporeal Shockwave Therapy

What is Extracorporeal Shockwave Therapy?

Extracorporeal shockwave therapy (ESWT) is used to decrease pain and improve healing in conditions affecting muscles, joints, tendons, or bone.

What conditions is ESWT used for?

ESWT can be used for many orthopedic conditions in dogs, including:

osteoarthritis
soft tissue strains (tendinopathies)
pain management
fractures that aren’t healing normally (delayed or non-union fractures)

How does ESWT work?

Contrary to its name, ESWT is not a form of electro-shock therapy, but instead uses sound waves to influence tissue changes. Unlike therapeutic ultrasound, the sound waves produced during ESWT are very fast (high velocity), very high pressure, and don’t generate heat.

ESWT starts as a sudden change in pressure that causes high energy sound waves to be released. This process is similar to a bolt of lightning rapidly changing the air pressure and causing sound waves in the form of thunder that may rattle your windows. While thunder is a very unfocused form of shockwave, ESWT uses focused, high-energy sound waves (shockwaves) to transmit energy into tissues.

"When used appropriately, ESWT can result in decreased pain, decreased inflammation, and improved healing of both bone and soft tissue."

As the waves pass through the layers of tissue, skin, subcutaneous tissue, fascia, muscle, etc., they release energy that stimulates a change in these tissues at the cellular level. By using the right setting and positioning, ESWT can target specific areas like tendons and joints. When used appropriately, ESWT can result in decreased pain, decreased inflammation, and improved healing of both bone and soft tissue.

What are the different types of shockwave therapy?

There are three different ways of generating shockwave energy: piezoelectric, electromagnetic, and electrohydraulic. Radial pressure waves have been used as an alternative to ESWT and are sometimes referred to as radial shockwave therapy. As radial waves are lower in pressure, and don’t penetrate tissues as deeply, some specialists don’t feel they meet the specifications to be called shockwave therapy.

Because different ways of generating shockwaves have different effects, therapy protocols differ based on which type of sound wave generator is used. There is no known “best” type of shockwave therapy at this time. The applicator used to deliver ESWT is often called a “trode.”

How long does treatment last?

Generally, ESWT is given as a series of treatments and positive results may not be seen for several weeks. The number and frequency of treatments varies depending on the device used and the condition being treated. Your pet’s rehabilitation veterinarian will be able to review the details of their treatment with you.

"The number and frequency of treatments varies depending on the device used and the condition being treated."

Some pets require sedation for treatment as certain devices can be uncomfortable or loud during application. Newer devices often don’t require sedation and some pets may even become more relaxed during treatment.

Does my pet’s fur need to be shaved?

Fur can create air pockets between the trode and the skin, which lessen the impact of the shockwave, reducing the amount of energy delivered to the target tissue and resulting in less effective treatment. Any fur over the treatment area will be clipped short. Ultrasound gel will be used to further reduce any air between the trode and the skin to maximize treatment effectiveness.

Are there any contraindications to using ESWT?

ESWT should NOT be used in:

dogs with immune-mediated joint disease
dogs with infected joints
dogs with infected intervertebral discs (discospondylitis)
dogs that are growing
dogs with neurologic deficits

Dogs on medication or with disorders that interfere with their ability to clot may experience more bruising, so ESWT is not generally recommended.

This treatment should not be administered over the lungs, brain, heart, pregnant uterus, or over major blood vessels or nerves. ESWT cannot be used over areas of infection, cancer, unstable fractures or overactive growth plates and needs to be used with caution over any implants.

Are there any side effects of ESWT?

ESWT can result in small bruises or temporary swelling. Sometimes, there will be some discomfort or a slight worsening of your pet’s signs for two or three days, so your pet’s rehabilitation veterinarian may prescribe additional pain medication for a short time.