Extracorporal Shock Wave Therapy (ESWT) is something that has been around for awhile but I suspect it will be coming into its own. I believe it will be taking increasing importance in the stem cell field. As an orthopedic surgeon I used this therapy a number of years ago for both tennis elbow and heel spur syndromes. Not only did I use it but I had good results with it. It fell out of favor due to the fact that it was not reimbursed by the insurance industry.
Recently I became aware of it again for its use in sports medicine and musculoskeletal problems. It is undergoing a renaissance of sorts and becoming popular outside the United States. I think we are now understanding better the true mechanisms of how this is working. While I was recently lecturing in Brazil I met one of the worlds experts on shock wave therapy, a professor from a university in Munich Germany. We had quite a good discussion concerning the use of shock wave therapy in stem cell and PRP therapy. At that meeting, I had an AH-HA moment when I realized that years ago when I used this technique I was actually creating an environment very conducive to stem cells. There were some surprising facts concerning the use of the shock wave machines. They create a momentarily pressure that would be equivalent to an ocean depth of approximately 2000 ft. Luckily this pressure only lasts a fleeting moment. Under most conditions this would cause immediate destruction of the tissue and probably death. The machine works on a principle of two metal objects hitting each other at a speed of 50 miles per hour. This is the inner workings of the machine. It works on an air gun principle making one piece of metal hitting into another at the speed of fifty miles per hour. This creates a shock wave that is transferred to the tissue.
What the shock wave actually does is create a bit of trauma to the area. This trauma also releases growth factors. In some respects this is similar to those physicians that are proponents of prolotherapy. In prolotherapy, some type of irritant such as high concentrations of dextrose (essentially sugar water) is injected into a tendon area or a joint. The idea is that the irritating solution will cause an inflammation. It is hoped that the inflammation will release some growth factors which may help in the healing process.
These growth factors are what seems to begin the cascade of healing. When ESWT is performed it releases among other factors Vascular Endothelial Growth Factor (VEGF). VEGF is responsible for creating a vascular supply where there typically is not any. The lack of a vascular supply is what helps to cause many problems such as tendonitis. It is also thought that the ESWT releases certain growth factors that enable stem cell homing to a certain area. This has been demonstrated by some fairly nifty experiments. In these experiments, stem cells were tagged with a tracer and were than injected into the body via an intravenous route. It was found that the cells seemed to congregate to the areas where the shock wave therapy was performed. Another important aspect of shock wave therapy is the formation of Nitric Oxide. We are now starting to realize that Nitric Oxide (NO) is one of the holy grails of stem cell therapy. NO has many different tasks in the body. We now know it is an extremely important signaling molecule in the body. It is known to be a growth, immune, and neuromodulator as well as a stimulator of stem cell proliferation. It has critical roles in analgesia, vasodilation and ATP production. Its release in the body is caused by many different factors. Laser light therapy is one such important aspect. When we start combining shock wave therapy with laser therapy than we may stimulate significant amounts of NO. Here comes the exciting part. When we start combining the shock wave therapy with the some the the regimens that we already have than will probably be a game changer. Using shock wave therapy with Platelet Rich Plasma (PRP) and or Stem cells will dramatically improve results.
I do not know if shock wave therapy itself will be total game changer but I do know it will be an increasingly important part of our ever expanding armamentarium of treatments. I am sure there will be more to come concerning this therapy. I believe this will become an increasingly important aspect in the utilization of PRP and Stem cell therapy in the treatment of hip, knee and other joint problems.
Thanks Dr. P.