Extracorporeal Shockwave Therapy: Hope Or Hype?

By Lowell Scott Weil, Jr., DPM, MBA; By Patrick A. DeHeer, DPM, with Stephen M. Offutt, DPM, Gary A. Trent, DPM, and Michael J. Baker, DPM

Pointing Out The Lack Of A Clear, Proven Treatment Protocol
On another line of thought, I like to know how and why procedures work. I have yet to find an understandable and proven explanation of how and why ESWT works. First MPJ arthrodesis is one of my favorite procedures and I am reassured by the fact that it has not changed much since its inception in the 1890s. I understand the hows and whys of it. At the same time, I really dislike first MPJ implants based on my understanding of the hows and whys of that procedure.
As with the disagreement among surgeons over ever changing implant designs, it seems that nobody can agree on the type of shockwave, pulses, settings and number of treatments to use. Do we use high-energy or low-energy waves? How many pulses? Should they be of variable settings or all the same? How many treatments does it take (multiple with low-energy or one with high-energy)?
Consider this statement from an article by Boddeker, et. al, in Clinical Rheumatology: “Despite an extensive use of ESWT, treatment settings have not yet been established and the mechanisms of its postulated antinociceptive effects are still unclear.” I think that the unknown mechanism of action has led to this confusion and hinders establishment of therapeutic standards that could be implemented in providing a valid prospective, double-blind, long-term study that would shed some light on this procedure.
Critical review of current studies reminds me of comparing apples to oranges. Take for example the much-publicized JAMA study by Buchbinder, which found “no evidence to support the beneficial effect on foot pain, function and quality of life of ultrasound-guided ESWT over placebo in patients with ultrasonic proven plantar fasciitis 6 and 12 weeks following treatment.”
What does this low-energy study mean when compared to the Weils’ 2002 JFAS study, which shows an 83 percent success rate with high-energy treatment? I really don’t know but it does add to confusion with regard to efficacy. Because of this lack of definitive procedural protocol evaluation, the efficacy of ESWT really cannot be established. Boddeker’s article further states: “It is concluded that at this point the efficacy of ESWT can be neither confirmed nor excluded. Randomized and controlled clinical trials are required to adequately estimate the value of ESWT as a treatment for plantar fasciitis.”

Raising Questions About Potential Complications And Long-Term Results
Finally, what about potential complications and, especially, long-term success rates? There really are not any studies with more than a three- or four-year follow-up. While I realize that we are dealing with a new procedure, if we don’t know how and why ESWT works, how then can we predict the potential of recurrence rates? I feel that we cannot.
I understand how orthotics and stretching provide long-term success rates for plantar fasciitis, but I am simply not sure how ESWT will prevent the re-straining of the plantar fascia if the patient is overweight, has poor foot mechanics, selects inappropriate shoe gear, has an excessively high activity level or works standing for long periods of time on hard surfaces. Only properly conducted patient trials over a longer period of time can answer these questions.
One should consider the possibility of recurrence and discuss it with the patient during the consent process. Although the literature has reported few complications, periosteum detachments, small fractures of the inner surface of the cortex, neurologic symptoms, plantar fascial rupture when done following multiple cortisone injections, lateral column and peroneal tendon pain have been reported in the literature for high-energy treatment. While high-energy treatment seems to be more efficacious than low-energy treatment, it apparently is associated with more potential complications, leading to still more questions on the standard of therapy. The potential to cause compartment syndrome would also seem to be a valid concern when evaluating potential complications, though it is not specifically mentioned in the literature.

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