How does a therapy that has proven itself over 5 decades become even better? Leave it to the US Navy to find a way.

Warming target tissues through the use of diathermic therapy is certainly not a new invention. For more than 50 years, the application, actions, and effectiveness of diathermic techniques have been extensively used and studied. While some older diathermy technologies, such as microwave diathermy, proved problematic, newer radio-frequency (RF) diathermic approaches have consistently been found to be safe and effective in the treatment of muscular, soft tissue, and even vascular disorders.

Until recent advances in diathermic warming technology came about, the principal drawbacks have been practical, not medical. The cumbersome nature of traditional RF diathermy devices and their technician- or clinician-reliant application has prevented RF diathermy from becoming widely used despite its well-recognized efficacy. In the meantime, less-effective modalities such as ultrasound have gained popularity primarily because of simplicity and convenience of use.

In 1986, the US Navy was researching ways to treat hypothermia in its divers. After exploring many options, they selected RF diathermy and developed a modality that overcame the limitations of traditional diathermy and other heat therapies. Only RF diathermy heated safely, penetrated deeply enough into the tissues, and was easily controlled.

Borrowing on this US Navy technology, diathermy has returned to the forefront of physiotherapies. Instead of using bulky equipment that beams down on a patient, RF diathermy can now be administered via easy-to-apply wraps. The result produces effective warming over a larger area than can be accomplished with older diathermy or ultrasound. New diathermy units can treat areas 12 times larger than ultrasound in the same time.

How Does This New Technology Work?
“The Navy-developed resonant RF warming coils use a helical geometry in a less-localized application of RF fields,” explains RG Olsen, PhD, a US Navy medical researcher and inventor of the new helical coil system. “The resonant nature of the tissue-plus-coil system causes an internal energy field that is directed lengthwise along the irradiated body part, within the coil’s windings; therefore, the wet tissues are efficiently warmed while the fatty tissue is not overheated.”

How Does New Technology Compare to Other Modalities?
Hot Packs—Hot packs have been shown to penetrate only 1¼2 centimeter to the applied area. With the thermal barrier of the subcutaneous layer of fat, they provide only superficial heat. This problem is compounded by the cooling effect of the increased blood flow into the area being heated. Recently, many insurance companies have stopped providing payment for hot-pack treatments in the office. The main advantage of hot packs, however, is their ease of use and unattended application.

Ultrasound—Ultrasound will penetrate from 3 to 5 centimeters into the body; however, it first warms the bone and muscle areas. Then, in reduced form, it perfuses to the target muscles and nerve tissue. Ultrasound is also an attended therapy requiring either the doctor or a staff member to be present throughout the treatment time of 15 to 20 minutes. In the lumbar region, for example, the transducer head must be constantly moved around to avoid burning tissues. The small head size also limits the size of the area that can be treated.

Diathermy—New diathermy systems use a low-energy longitudinal warming field, which penetrates 3 to 5 centimeters into the body. However, instead of penetrating perpendicularly to the active field, it radiates longitudinally. This allows the target areas of muscle and nerve tissue to be brought up to the initial warming threshold of 40° C within 5 minutes. US Navy research indicates a patient’s tissue temperature reaches the therapeutic ceiling of 45° C at the end of the 20-minute treatment. The FDA considers temperatures between 40° C and 45° C to be therapeutic.

According to James Giordano, PhD, director of research at the Moody Health Center in Houston, “Radio-frequency diathermy is and should continue to be an important therapeutic modality, and the current technically advanced systems will make diathermic therapy available to a much wider range of patients than ever before.”

Older diathermy devices were bulky, inconvenient, and awkward to use. They also used a high-energy perpendicular field that presented a risk of thermal injury to the patient, requiring strict supervision of a trained therapist or technician.

New RF diathermy units have developed a computer-controlled output module that is coupled to specific body wraps. Rather than having to position equipment over the target area, it can be wrapped to cover all three dimensions of the target area. The combination allows the system to be started, and then left safely unattended throughout the entire treatment cycle. It is so safe that the FDA allows the diathermy unit to be turned on and off by a nonlicensed professional.

Clinical field tests on new diathermy units indicate that it is very effective for pain and musculoskeletal problems. Brenda Cobb, a scientist with Brooks Air Force Base, San Antonio, noted that, “As both a scientist and a patient, I strongly recommend RF diathermy for pain management. I have had several sessions with this new type of heating device and find it very effective in reducing the pain associated with myofacial pain syndrome and fibromyalgia. Unlike traditional heating methods, RF diathermy provides deeper, longer-lasting heating due to its penetrating properties in tissue.”

Diathermy also has been adopted by a number of professional sports teams. Jim McCrossin, CSCS, ATC, head athletic trainer for the Philadelphia Flyers hockey team, recently switched to the new diathermy system. “Professional hockey is a very tough sport. Players are always getting bruises, sprains, fractures, and other injuries. I have noticed a dramatic reduction in healing time from injuries since we began using diathermy. Pain is reduced, and range of motion is greatly improved. The players love it, and so do I!”

Regarding Reimbursement
Leslie R. Miller, owner of Automated Physician Services, a national billing service, has seen a recent rise in diathermy billings with the new technology. “Short-wave diathermy is considered reasonable and necessary for the delivery of heat to deep tissues. It is used for areas such as skeletal muscles and joints, and for the reduction of joint-pain stiffness and muscle spasm. The reimbursement is approximately $6 to $16 when coded as 97024.”

Bottom Lines
As physicians, we must keep up with the advances in medical technology. The new diathermy technology offers therapeutic deep heat that is both unattended and reimbursed—two major advantages over the standard hot packs and ultrasound. The evidence also shows that the treatments can be administered faster due to the longitudinal field generated by the target-area wrap. This is a distinct advantage over the older perpendicular equipment.

Even though the target area reaches the therapeutic warming threshold faster than the other modalities, some advanced diathermy units can be used unattended. This is due to the specially designed RF generator interface with the garment wraps, which modulate the entire treatment cycle.

The new systems are much more portable than the older, larger units. The form-fitting wraparound garments are easily stored in a drawer next to the RF generator, which has been reduced to the size of a portable radio.

Seeing the clinical advantages that diathermy is now offering, along with the offer of an unattended and reimbursable treatment system, it seems like it is time to take another look at diathermy. CP

Mark Mandell, DC, MBA, is the president of BrainStorm Group, a marketing and regulatory consulting firm for chiropractic and health care product companies. He can be reached at (732) 257-2463 or via the Web site www.BrainStormGRP.com;   Ivan Delman, DC, is the author of The Business of Chiropractic and a consultant with BrainStorm Group. His book and articles can be seen at www.BusinessofChiropractic.com.