For the past three years, musculo-skeletal extracorporeal shock wave therapy (MS-ESWT) has become a topic of much discussion in the American podiatric and orthopedic communities

As a result of a dearth of peerreviewed American literature on MS-ESWT, skepticism and cynicism exist among some practitioners and third-party carriers.

MS-ESWT is controversial for a multitude of reasons. As a non-invasive therapy, it is widely embraced as a safer alternative than open surgical procedures. The mechanism of action is speculative, difficult to quantify and prove, and still undergoing extensive research both here and abroad. MS-ESWT technology is very expensive-thus the cost of treatment is almost equivalent to an open surgical procedure. Many insurance companies have embraced the technology due to the lack of invasiveness, the minimal side effects and the rapid return to work and the activities of daily life for their subscribers. Other companies have been reluctant to cover the procedure until more studies are published.

While ESWT has been proven effective in literature from around the world, there have been very few randomized, prospective, placebo-controlled, doubleblinded studies performed. In a recent study published in the Journal of the American Medical Association, low dose MS-ESWT was found to be no more effective than placebo in the treatment of plantar fasciitis. However, a careful review of this study revealed serious flaws in the methods and conclusions.

As the largest market in the free world, the U.S. has seen ESWT companies attempt to get their products FDA-approved for marketing and sale. Currently, only three machines have been FDA approved for the use on humans, two for plantar fascitiis and one for lateral epicondylitis (tennis elbow). There are at least three other companies currently conducting FDA clinical trials in the U.S.

New Concepts

"New Concepts" is a forum for the presentation of new technologies and products which have been the subject of clinical study. Readers should be aware that Podiatry Management does not specifically endorse any of the technologies, concepts, or products being discussed.

Cynicism exists amongst some practitioners and third-party carriers.

Historical Background

The history of ESWT dates back to WWII, when it was discovered that shockwaves have an effect on humans. During WWII, submarines were attacked with depth charges and in many situations were left without any structural damage, but members aboard the submarine had either perished or had been seriously injured. At autopsy, significant organ damage, specifically to the lungs, was found. It was therefore understood that the shockwave generated from the depth charge explosion could cause significant damage to humans while sparing the submarine. Shockwave was employed medically in the early 1980s when it was introduced as lithotripsy for the breaking up of renal stones. Both extracorporeal and intracorporeal shockwave are often utilized to break up the plaques and allow stones to pass without the need of riskier, more invasive procedures. In 1986 shockwave was found to have benefits in wound healing as well as the healing of fractures. Later in the 1980's, shockwave was utilized to loosen cement for facilitating prosthetic removals. In 1992, shockwave began to be utilized for treatment of tendonosis and plantar fasciitis, and in 1993 it was first utilized for calcific tendonitis of the shoulder.

How It Works

Shockwave incorporates a sonic pulse with a high peak pressure of 50 Mpa, a short lifecycle of approximately 10 milliseconds, a fast rise in pressure of less than 10 nanoseconds and a broad frequency from 16 Hz-20 MHz. High stress forces cause cavitation, which is defined as the movement of bubbles of gas in a fluid. This is how shockwave energy is transmitted into the body. The device that is creating the shockwave causes these cavitation bubbles that move at speeds of 700 meters per second, creating significant energy that enters the body. This cause and effect results in a transient increase in cell membrane permeability.

Shockwave Technologies

There are four different technologies that are currently utilized to create medical shockwave: electrohydrolic, electromagnetic, piezoelectric and radial.

The electrohydrolic system is also known as sparkgap technology and accounts for the first generation of shockwave machines. A spark plug is used to generate heat and a sonic pulse, resulting in cavitation.

The electromagnetic principal was first described in1962 by Eisenmenger. An electric current is passed through a coil, producing a strong magnetic field. The compression of the fluid then creates a shockwave.

The piezoelectric principal employs a high voltage current, which is applied to a substantial number of piezo crystals mounted on the inside of a sphere. The piezoelectric effect causes deformation of the crystals, inducing a shockwave.

The focal point or area of maximal therapeutics is at some fixed distance away from the shock wave generator in the electrohydraulic, electromagnetic and piezoelectric machines.

The radial principal has a focal point that differs from the other three technologies. The focal point of the radial principal is directly at the device-skin interface and is dispersed in a megaphone fashion from the head of the radial device.

Two ESWT Systems Differ in Shock Source and Power Level But Both are FDA-Approved

Dornier's Epos Ultra and Healthtronics' Ossatron systems are currently the only FDA-approved ESWT treatments for plantar fasciitis.

Following more than a decade of extensive research in the field of orthopedic shock wave applications, Dornier MedTech received FDA approval in 2002 to market its Epos Ultra device for the treatment of plantar fasciitis. The Epos Ultra has been successfully used, however, on thousands of patients in other parts of the world for many years now.

The Epos Ultra is the only device on the market to include an imaging system. Ultrasound provides precise localization and excellent imaging quality, allowing the user to continuously observe and control therapy. The treatment area can be viewed from various angles, and a crosshair is depicted in the image to indicate the exact therapy focus. Epos patients aren't put to sleep during the procedure, which lasts approximately a half hour.

Because of its unique shock source (electromagnetic shock wave emitter), the Epos Ultra can treat at versatile power ranges- from low to medium to high energy levels. Moreover, no expensive spark-gap disposables are necessary to generate shocks.

With a footprint of only 37" x 24" (l x w), a height of only 43" and a weight of 275 pounds, the Epos Ultra is small, light weight, easily transportable- and very quiet to operate. Simply plug it in to a power outlet, switch it on-and it's ready to use.

FDA investigational studies using the Epos Ultra took place at Emory University School of Medicine in Atlanta, Henry Ford Health System in Detroit and Mass General in Boston. Over 60 percent of study participants experienced good to excellent results at three months. Their mean pain score decreased from 7.7 to 3.4 at three months (10 being highest pain level), to 2.2 at six months and 0.6 at 12 months-or a 92 percent reduction in pain at 12 months.

Dornier MedTech (www.dornier.com) is a privatelyheld company that develops, manufactures, markets and services lithotripters, orthopedic shock wave devices, urotables and medical-aesthetic lasers. For more information, contact Dornier MedTech America at 1- 800-367-6437 , or circle #140 on the reader service card.

The OssaTron® from Healthtronics is a high-energy shockwave system that provides a non-invasive surgical alternative for patients diagnosed with chronic pain caused by excessive strain on joints and tendons. Using a unique non-invasive process known as Orthotripsy ®, the OssaTron® emits shock waves, similar to those used to treat kidney stones, at the point of attachment of tendons to increase blood flow, which stimulates healing of the affected area. Shockwaves alter cell metabolism and generate mechanical stimuli, which result in neovascularization. In both calcific and non-calcific tendinopathies, calcific deposits are reabsorbed and degenerative tissue areas are revascularized. The OssaTron® ESW system provides maximum penetration depth, broad energy range, and a large focal area to create a clinically effective ESW system.

The OssaTron® device utilizes the electrohydraulic principle in generating high-energy sound waves. The approach involves submerging an electrode known as a spark plug in a water-filled housing. The OssaTron®'s electrohydraulic generator initiates the shock wave by producing an electrical spark between the tips of the electrode. The spark vaporizes the water between the tips of the electrode, producing an explosion that creates a spherically shaped shockwave.

A metal semi-ellipsoid reflector reflects the shock wave and focuses it onto the patient's heel, where it is coupled to the treatment head, and the maximum amount of energy is delivered to the targeted region.Due to the way the shockwave is created, the OssaTron® can deliver more energy per shock into the body than low energy devices. As the energy level on the OssaTron® is increased, the focal area actually increases. The OssaTron®'s broad focal area and wide selection of energy settings (from 14kV to 28kV) help ensure that physicians can deliver the proper amount of energy to an appropriate area to treat each indication.

FDA studies were conducted in multiple centers to assess patients treated with the OssaTron ® for chronic proximal plantar fasciitis. Following treatment with 1,500 shocks (18kV, 2Hz) all 310 patients who received an actual treatment were reassessed by Roles and Maudsley outcomes grading. Excellent and good ratings were evident in 81% of the patients.

Dr. Kent Feldman of San Diego, Calif. has reported great success with the OssaTron®. He recalls one patient, an occupational therapist, who had suffered from heel pain for two years and tried a variety of conservative treatments. Within a week of receiving her OssaTron® treatment, the patient showed a 90 percent improvement and returned to her normal activity.

The OssaTron is not a panacea for curing plantar fasciitis. Patients should be treated with the OssaTron only when they have failed other conservative treatment options. For more information, contact Healthtronics at 800-464-3795 , visit www.healthtronics.com, or circle #141 on the reader service card.

Several other companies currently have clinical U.S. FDA studies in progress, with anticipated availability in the near future:

UMS (Wolf Piezoson 300): email gwoolston1@cox.net or circle #142 on the reader service card.

EMS (Swiss DolorClast): email pkroener@ems-medical.de or circle #143 on the reader service card.

Orthometrix (Orbasone) (formerly Norland): email rbonmati@aol.com or circle #144 on the reader service card.

Mechanisms of Action

There are several postulates regarding the mechanism of action of shockwave. Research by Wang described the mechanism of MS-ESWT as multiple micro traumas that promote neo-vascularization to the tissue that is being treated. Others have compared the process to that of tenderizing meat, whereby repeated pounding on the meat will break up the interstitial fascia or scar tissue, thus making the meat more pliable. Several different musculoskeletal conditions that have been treated with shockwave are tendonitis, calcifying tendonitis, periarticular shoulder calcification, tendonitis calcareus, plantar fasciitis, medial and lateral epicondylitis, osseous non-unions and avascular necrosis. Differences Among Technologies Currently, there exists no consensus concerning the use of low-energy shock waves (requiring no local anesthesia) and high-energy shock waves (requiring local or regional anesthesia) for the treatment of chronic plantar fasciitis. Indeed, there is no consensus thus far even regarding how to differentiate low-energy from high-energy shock waves, as multiple physical parameters are involved. While the clinical effect of both protocols appears to be comparable, as discussed below, there is evidence of increasing side-effects as increasing energy levels are applied. Although these side-effects do not appear to be significant from a macroscopic view, local tissue and nerve tissue may be affected. A low-energy treatment regimen makes deleterious side-effects extremely unlikely compared to an application of higher energy flux densities. No local anesthesia is required, so related side effects are lacking. A "disadvantage", however, is that a repeated application is usually required.

Pricing Extracorporeal Shockwave Therapy

The early months of 2003 appear to be a flurry of activity surrounding reimbursements, referrals, and pricing for extracorporeal shockwave therapy (ESWT). While no permanent CPT code has been assigned ESWT, Medicare at first introduced a payment policy based upon a new plantar fasciitis extracorporeal shockwave therapy temporary code, 0020T, with the following values:

Physician Work RVUs: 0.06
Practice Expense RVUs, non-facility: 1.46
Practice Expense RVUs, facility: 0.02
Malpractice RVUs: 0.01

So, using code 0020T: if you as the treating physician were to perform ESWT on your patient in a facility (e.g., ambulatory surgery center), your total RVUs for 0020T would be 0.09; if you performed the treatment in your office, you would be allowed 1.53 RVUs. To put this into perspective, if you performed ESWT in the office, Medicare would pay you less than you would receive from performing a simple I & D, but more than debriding partial skin. If you performed extracorporeal shockwave therapy in an ASC, Medicare would pay trimming 1-10 nails (CPT 11719) at twice the allowance you would receive for being the treating physician for ESWT; or, better yet, if you removed (if only you could) ear wax from a patient, Medicare would pay you 9 times as much as you would receive as the treating physician in an ASC on an ESWT case.

APMA quickly mobilized its forces to fight Medicare's notion that the performance of extracorporeal shockwave therapy is similar to the administration of a physical therapy modality. The recently-announced result of their efforts is that the Centers for Medicare & Medicaid Services (CMS) have said that they will withdraw the new payment policy for extracorporeal shock wave therapy (ESWT) for plantar fascia for further review. CMS will return to carrier-based pricing instead of the relative value units announced in December for the 2003 physician fee schedule. According to one source, APMA's letter to CMS was an important factor in the Medicare agency's turnabout. "This shows that APMA can reach high-level decision makers at CMS and resolve key issues, many of which are never publicized," said APMA Vice President Lloyd S. Smith, DPM, chair of the Health Policy Committee that has coordinated the Association's response to CMS. "We really appreciate all of the information from members about ESWT research and how carriers in different states are reimbursing physicians for this service. We were able to demonstrate mistakes and problems with the policy, which prompted CMS to reconsider it."

APMA has requested that Medicare use the Relative Value Update Committee (RUC) to set the payment level for the ESWT code. If CMS decides to issue a national coverage decision, APMA will try to work directly with the agency to get the best possible policy. Since verbal assurances are not official Medicare policy, APMA will look for CMS to officially announce this change soon in a fee schedule correction. If and when that happens, APMA will notify members.

But enough about Medicare, let's talk about non-Medicare payers who don't know how to read the Federal Register or the Journal of the American Medical Association.

How is extracorporeal shockwave therapy priced? Actually, there are two schools of thought on the reimbursement. The first, primarily promoted by the ESWT marketers, is "global package" billing consisting of a single fee covering all costs. While there are some thirdparty payers who reimburse "globally", others are breaking down the actual treatment and ancillary components into individual reimbursable segments. When I advise third-party payers on ESWT reimbursement, I recommend the non-global payment method. I divide reimbursement into 4 areas:

• Professional (Treating Physician) Component - should be billed either as CPT 28899 or CPT 0020T (category III CPT code), depending on the individual payer.
• Technical Component - should be billed as CPT 28899-TC or CPT 0020T-TC (category III CPT code); includes both the technician and ESWT unit use/rental.
• Facility (minor treatment room including preand post-recovery room use) Component.
• Anesthesiologist/Anesthetist Component - should be billed per usual, customary, and reasonable codes/rates.

Extracorporeal shockwave therapy should always be pre-authorized. While obtaining pre-authorization, inquire regarding the payer reimbursement for the procedure. Be ready to submit copies of the patient's medical records to evidence when the patient first reported heel/arch symptoms, when the diagnosis of plantar fasciitis was made, what active treatments you have performed to date, and how your active treatments have failed to reasonably eliminate or control the patient's plantar fasciitis symptoms.

Others have compared the process to that of tenderizing meat.

JAMA Trial

As to the JAMA trial: Buchbinder et al. enrolled 166 patients in a double-blind, randomized, placebo- controlled trial. Patients were randomly assigned to receive either ultrasound-guided ESWT given weekly for three weeks to a total dose of at least 1J/mm_ or identical placebo to a total dose of 0.006 J/mm_. After significant improvements in both groups, the between-group difference of improvement was only 6 mm on a 100 mm visual analog scale. There was no evidence of ESWT being superior to the placebo. The study of Buchbinder is of excellent quality, but there are some points to be discussed.

First, patients in the active group did not receive identical treatment (either 2000 or 2500 shock waves per treatment of energy levels varying between 0.02 mJ/mm_ and 0.33 mJ/mm_). Second, the mean total dose in the active group was 1407 mJ/mm_, 1000 mJ/mm_, more than is commonly used. In the experience of the author, patients will not tolerate such a high-energy flux density unless the treatment area of maximal pain is missed or anesthesia is provided.

Accordingly, third, Buchbinder did not focus on the area of maximal pain, but on the area of maximal thickness of the plantar fascia. Fourth, a potent analgesic drug was allowed for the duration of the study. Fifth, patients were enrolled with a pain history as short as six weeks, contrary to six months in our FDA studies. Sixth, there was no real placebo group, but sham therapy consisted of application of 100 shock waves of 0.02 mJ/mm_. Seventh, the plantar fascia was diagnosed as pathologic even when the thickness was within a standard deviation of normal thickness.

ASFAST Develops Protocols, Evaluates ESWT Results

The mission of the American Society for Foot and Ankle Shockwave Treatment (ASFAST) is to develop protocols and evaluate results of ESWT around the foot and ankle, share information regarding reimbursement issues, and to interact with the larger shockwave societies within the USA and worldwide.

The society membership is open to practicing professionals (DPM, MD, DO) who have an interest in ESWT. For more information and an application for membership, contact:

John Moroney
Executive Director, ASFAST
1945 N. Burling, Chicago, Illinois 60614
847-980-0896
ASFASTJM1@AOL.COM

A considerable placebo effect of approximately 30% can occur with low-energy ESWT.

Conclusions

There is no doubt that a considerable placebo effect of approximately 30% can occur with low-energy ESWT in patients with plantar fasciitis. (Rompe) Randomized controlled trials applying 1000-2000 low-energy shock waves exactly to the area of most pronounced tenderness over the medial aspect of the calcaneus, without use of local anesthetic, have reported successful outcomes in about 60% of patients with a chronic plantar fasciitis three to six months after the last ESWT.

Stringent patient selection appears to be a key issue, regardless of the type of energy utilized. Patients involved in the aforementioned study were facing the worst-case scenario with chronic pain over the medial aspect of the calcaneus for more than six months, and several conservative treatments had failed, including local injections, physical therapy, and NSAID medication.The indication in every case had been for surgical treatment, yet in Rompe's study ESWT led to a >50% decrease of pain in 76% of patients, compared with 35% in the control group.

The technique of application also appears to be a key issue, again regardless of the type of energy utilized-- it's important to deliver the shock waves exactly to the area of maximum pain over the heel.

In summary: ESWT can be regarded as a non-invasive, safe, and profoundly studied alternative to invasive, potentially risky, and poorly evaluated surgical procedures.

Of course, further randomized controlled studies are required to establish optimal criteria for selection of patients and for selection of treatment parameters. Our recent study of 40 patients using a single treatment of high energy MS-ESWT revealed a successful outcome for 82% of patients and an improvement of 60% from baseline at 9 months post treatment. We are currently involved with three separate randomized, prospective, placebo controlled, double blinded studies on MSESWT: a piezoelectric device, an electrohydraulic device, and a radial device.