Page 24 - 12 April 2013

Shock wave therapy is used to treat lameness
yet where it hits the focus area - a bone, or where a tendon attaches - it has an effect,” he explains.
“In humans, this technology was being used to break up kidney stones, and the patients reported that their arthritis hurt less. Some of the benefits were discovered by accident. It seems to stimulate healing, prob- ably by energizing interleukin 1 and other chemical messengers in the body that stimu- late the actual healing. Research has shown that interleukin 1 is stimulated by shock waves. We also know it increases blood flow, which is essential for healing,” he says.
“Shock waves are produced in a couple different ways. The machine I use has a small air compressor that sends a small plunger forward, making it move very rapidly against the skin as you hold it tight against the horse. This movement sends an energy wave just by physically hitting the skin. We use a gel on the skin, like for ultra- sound, and this helps transfer the energy from that little plunger. It moves so quickly that you can hardly see it move,” he says.
“This transfers the energy into and through the body’s soft tissues like a wave going through water. It just keeps going until it hits something it can’t go through. When it hits the interface of two different struc- tures, such as bone and ligament or muscle and bone, this is when it deposits most of
its energy. One of the places we use shock wave is where a tendon attaches to a bone.
It hits that attachment and all the energy is deposited right there,” says Connally.
“People used to think it caused little micro-fractures of the bone. We now know it doesn’t do that, but we are still not sure how the energy stimulates release of chemical mediators - the chemicals that signal messages to the body cells.” This augments what the body’s own messengers do to help heal an injury. Perhaps it gives them a bigger jolt to get going.
Immediately some of these messages cause blood vessels to dilate, thus allowing increased blood supply to bring in all the necessary ingredients for healing, such as more oxygen and nutrients and all the little building blocks necessary for repair. “The nice thing about shock wave is that we can use it on and around wounds to stimulate the blood supply and chemical messengers, without damaging the tissues - and help the wound heal faster,” he explains.
“We are still finding new uses for shock wave therapy. When it first came out, we thought it would be the best thing for navicular and several other problems we didn’t have good treatments for. We found
that it won’t cure navicular or injuries inside joints, but when shock wave is used we find chemicals in the blood that are markers of bone remodeling.”
These chemicals are released in the body when bone is actively being remod- eled or rebuilt. “This can help stimulate healing of small fractures, for instance. The increase in these chemicals showed that the shock wave was having an effect on bone remodeling. In human medicine and small animals, shock wave has been used to treat non-union fractures that wouldn’t heal. It was probably stimulating those bone cells to get busy and do more,” he says.
“Sometimes the healing process goes on for awhile and then seems to get stuck. It does this with bones and sometimes with wounds. The injury heals partially and then just stops and doesn’t make much progress. I have gone into some of these wounds and cut out some of the scar tissue. I’ve found that if I cut out the scar tissue and use shock wave therapy,
I have better success in getting the healing going again,” says Connally.
“The new machines are more user-friendly and treatment is not as painful. We used
to sedate the horses when using the older machines, but I don’t need to do that anymore. I don’t know why these hurt less, unless they have a better way of generating the energy wave without it being so violent,” he says.
Connally has used shock wave therapy on himself to give relief from painful injuries, particularly an old neck injury. “When I realized how well it worked for me, I became even more excited about using it on horses.”
“It’s important to understand that
this is a specific type of therapy, and not the same as laser therapy or therapeu-
tic ultrasound therapy,” says McClure. “Shock wave is much different technology. Depending on the type of machine, the pressure wave is produced by discharge of a high voltage spark under water or by elec- tromagnetic force, which is like a stereo speaker under water,” explains McClure.
The pressure waves/pulses are channeled and focused to pass through the body toward a target area. When they hit that spot, such as where a tendon attaches to a bone, the power of the pressure wave is released.
“With the portable, hand-held equip- ment in use today, we have been able to streamline the treatment. We no longer have to anesthetize the horses to treat them. We can do repeated treatments as outpatients. We often do a series of treat- ments that now cost what one treatment cost 10 years ago,” says McClure.
Equipment
The original machines were large and cumbersome, but they soon evolved into smaller, more user-friendly models. “The first 3 machines - that Dave McCarroll, Van Snow and I had - were the size of washing machines and cost half a million dollars apiece,” says McClure. Since then, shock wave machines have become more compact and portable, and also more affordable. A good shock wave machine can now be purchased for less than $40,000.
“During the past 5 years, however, they haven’t changed much. We’ve gotten some with a little higher energy and some longer cords, but the equipment is basically the same.” The big difference today, compared to 10 years ago, is the availability of this type of therapy and the growing number of people who use it.
Connally’s shock wave machine is very small and portable. “There are 2 kinds of shock wave - a radial version and a focused version. Mine is a radial version, which is less expensive, a little bit smaller, and doesn’t penetrate as deeply. The new focused units are also fairly small and portable. The old ones were too big, clumsy and hard to move. I keep mine in my Suburban all the time, so whenever I run across a patient that needs it, it’s there,” he says.
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SPEEDHORSE, April 12, 2013
equine health
Dr. Bruce connally