By: Daniel Trecroci
A big issue in diabetes care today is the prevention of foot wounds that could lead to serious consequences. Untreated foot deformities and calluses can lead to ulcers that can subsequently lead to infection and amputation. The American Diabetes Association (ADA) reports that 15 percent of all people with diabetes develop foot ulcers. Diabetic foot problems result in as any as 60,000 major amputations per year in North America.
There are measures that can be taken to prevent foot injuries. Managing your blood sugar is the first step for preventing these complications because poor diabetes control can lead to a person developing neuropathy. Arnie Davis, certified pedorthist and president of Davis Shoe Therapeutics in San Francisco, says that a person with diabetes should see a podiatrist, or foot doctor, on a regular basis if they develop neuropathy, which reduces a person’s ability to feel pain and sensation in their feet.
“Calluses and ulcers occur on high-pressure areas of the foot which meet the ground when you walk,” says Davis. “If a person has neuropathy and develops a callus on their foot, they will be unable to feel the pain associated with the callus.”
In addition to seeing a podiatrist for routine diabetic foot care to handle calluses and wounds, there are special shoes and products that can help the diabetic foot stay healthy and strong.
“Physicians need to understand that patient screening, education and use of [protective] footwear can substantially improve the quality of patient care,” says Michael S. Pinzur, MD, lead researcher and chair of the American Orthopedic Foot and Ankle Society Diabetes Committee. “At the same time, we want health insurers to know that providing therapeutic shoes and custom foot orthoses is more cost-effective than treating foot ulcers and infection.”
Neil Scheffler, DPM, FACFAS, of the Baltimore Podiatry Group in Baltimore, says that all patients with diabetes should have their podiatrist individualize what type of shoe they should be wearing.
“It is very important, perhaps the most important aspect of diabetic foot care, and is often overlooked,” says Scheffler. “Patients who have had ulcers and wear therapeutic shoes more than 60 percent of the time decrease the recurrence of ulcers by more than 50 percent over patients who wore these shoes less than 60 percent of the time.”
Scheffler adds that the type of shoe that a person with diabetes should wear depends on the condition that person is in.
“Every patient should be approached individually,” he says. “If you are 39 years old and you don’t have retinopathy, peripheral vascular disease or hammertoe, you don’t have to wear anything specific. If, however, you are an old lady who has hammertoe, neuropathy or can’t feel your feet, you need an entirely different type of shoe. I would usually prescribe a person with a bunion or hammertoe a custom-molded shoe. Maybe somebody else would need an extra-depth shoe with additional padding on the inside.”
Scheffler says that Medicare patients who qualify for coverage under the Therapeutic Shoe Bill are entitled to one pair of therapeutic shoes plus two or three pairs of othoses per calendar year (see sidebar).
Orthoses are shoe inserts that are intended to adjust an irregular walking pattern and accommodate foot deformities. Orthoses perform functions that make standing, walking, and running more comfortable.
“An orthotic device will diffuse areas of pressure and control excessive motion in the foot,” explains Davis.
Orthoses alter the angles at which the foot strikes a walking or running surface, thus minimizing stresses that could ultimately cause foot deformity and pain.
Davis says that a person who has no foot deformity but is losing sensation in a foot should be fitted for an orthotic device. If somebody has calluses but no foot deformity, Davis suggests buying comfortable shoes, removing the sole and purchasing a higher-grade orthotic device.
Ankle -Foot Orthoses
Davis says that upon prescription, orthotic devices are made from exact molds of the patient’s feet and are fitted into commercially made or extra-depth shoes. Davis also uses ankle-foot orthoses, or braces, that use the leg to stabilize the foot.
These are indicated for diabetic patients with neuropathy who are at risk for developing ulcers or skin breakdown. ProThotics are clinically proven to reduce pressure for patients with sensitive or ulcerated feet.
Davis recommends that people with diabetes wear white socks because they act as a flag for any problems that might occur.
“Wearing white socks lets you see if there is any blood or drainage from a blister,” says Davis.
Scheffler adds that he knows of no insurance company that will cover socks for the treatment and prevention of diabetic foot problems, but he still recommends them.
“I accept the benefits of diabetic socks,” says Scheffler, adding that it is important for a person with diabetes to look for certain characteristics in a sock, rather than to just wear a sock that is a labeled a “sock for people with diabetes.”
“I would recommend going to a shoe store to get a sock that has additional cushioning that wicks perspiration away from the skin,” he says.
William Tarran, DPM, chief-of-staff at Pacific Coast Hospital in San Francisco, says there are very few socks that are actually harmful for people with diabetes, but there are socks that are better.
“The important thing is that the socks don’t have seams that can violate the skin and they should be non-constrictive,” says Tarran. “Also, socks should be made of a breathable material that doesn’t hold moisture and are not prone to bunching up.”
Davis advises against wearing socks that are too thick.
“Thicker socks give more protective insulation around the foot but they will make your shoes tighter,” he says. “If a shoe is somewhat snug with a thin sock, it will be too tight with a thick sock.”
Davis advises wearing bigger shoes if a person wants to wear thick socks. If a person wants to wear thin socks, they should wear shoes that are more padded.
In a survey conducted last August at the 1999 American Association of Diabetes Educators Conference in Orlando, Florida, more than 90 percent of diabetes educators said that they would recommend the SensiFoot diabetic sock.
According to manufacturer Beiersdorf-Jobst, Inc., SensiFoot, is the “first and only diabetic sock that incorporates the benefits of gradient compression.”
“SensiFoot is designed to give people with sensitive feet added comfort and protection from rubbing and pressure points that can lead to skin damage,” said Claus Wiegel, president of Beiersdorf-Jobst, Inc.
SensiFoot incorporates a padded foot and heel, and moisture-wicking fibers to keep the foot cool and dry. The sock also has an anti-microbial finish to prevent growth of fungus and bacteria.
For more information on the SensiFoot sock, call 704-554-9933.
TheraSock Double Sock System
TheraSock, manufactured by TheraFoot Technologies, is a double-layer sock that helps absorb friction between the sock layers to guard against blisters, corns, calluses and other kinds of injuries. According to a recent study released by the Academic Hospital of Mastrich, Holland, TheraSock was discovered to prevent foot ulcers, reduce callus formation and prevent bed sores.
For more information, call TheraFoot at 888-466-0001.
The Silver-Thera Sock
The Silver-Thera electrotherapy sock, worn while sleeping, has been shown to reduce neuropathy pain and improve blood flow in 70 percent of a study group at the University of Texas. For more information, call Prizm Medical at 800-447-4422
Rx Comfort Socks
Manufactured by PTFE, LLC-Dx, Rx Comfort Socks are designed to help people with diabetes and other circulatory problems. The socks come with Blister Guard, which utilizes Teflon fibers that significantly reduce skin friction. This prevents blisters, abrasion, hot spots and calluses.
“From a physician standpoint, we found that Rx Comfort socks have indeed helped reduce the amount of deformity forces, such as blisters and calluses…that cause diabetic complications,” says Dr. John A. Mattiacci, dean of podiatric medicine at Temple University.
For more information on Rx Comfort Socks, call PTFE, LLC-Dx at 212-545-1783.
The FootSaver examines the soles of the feet, which people with diabetes are advised to do on a daily basis. Available at most major pharmaceutical stores, including Longs Drugs, the FootSaver is a mirror attached to the end of a lightweight aluminum pole with a molded grip, adjustable swivel and a telescopic handle. It is used to check for calluses, bruises and cuts.
“The Footsaver is simple in concept and use, yet it [could] save countless hours of treatment and thousands of dollars in medical costs,” says John Hollander, DPM, of the American Board of Podiatric Surgery.
According to researchers at the University of Washington, the incidence of foot ulcers in patients with types 1 and 2 diabetes is 2 percent per year. For diabetic foot wounds to properly heal, Scheffler says there is an abundance of saline dressings, skin creams, ointments, antibiotics and foams that are used for treatment. These are typically tried first and are usually inexpensive. If these do not work, other medications are taken into consideration.
Available by prescription in the United States since April 1998, Regranex, a growth factor medication, was given approval by the U.S. Food and Drug Administration (FDA) in December 1997 for the treatment of diabetic foot ulcers.
“Growth factor is what allows the wound to heal,” says Scheffler. “If the body doesn’t bring about healing by itself, Regranex will give it a boost.”
According to David Steed, MD, professor of surgery at the University of Pittsburgh, and a Regranex Gel clinical trial investigator, wound healing was a complex process that only Mother Nature could influence-until now.
“With Regranex, we have something that no drug has ever offered before,” he says. “A simple, easy-to-use treatment that actually stimulates the body to heal more diabetic ulcers.”
Clinical trials of Regranex demonstrated that a once-daily topical application significantly enhances and speeds up the healing of diabetic foot ulcers. The active ingredients of Regranex include becaplermin, a genetically-engineered, platelet-derived growth factor that mimics a protein that occurs naturally in the body. The growth factor stimulates the migration of cells to the ulcer site, encouraging the patient’s body to grow new tissue that heals these open wounds.
In clinical trials of almost 1,000 patients, Pexiganan, an investigational topical antibiotic derived from skin secretions of the African-clawed frog, was comparable to orally administered antibiotics when applied topically to diabetic foot ulcers.
While most antibiotics used for diabetic ulcers work by disabling a key bacterial protein, Pexiganan works by attacking the organism’s cell membrane, ultimately causing cell death.
Pexiganan, which is being codeveloped by SmithKline Beecham and Magainin Pharmaceuticals Inc., is currently under FDA review for the topical treatment of diabetic foot ulcers.
Apligraf was given FDA approval in 1998 for the treatment of leg ulcers.
Results of a Harvard Medical School study on 16 patients with diabetes showed that weekly applications of Apligraf for four weeks resulted in a higher healing rate when compared to control treatment. Apligraf was also not associated with any significant side effects, leading researchers to conclude that it may be a “very useful adjunct for the management of chronic diabetic foot ulcers, which are resistant to the currently available standard line.”
Already available in Canada and the United Kingdom, Dermagraft is a human-based skin replacement designed to promote complete wound closure and accelerate healing. Dermagraft provides a living, metabolically active human skin tissue capable of interacting with the wound bed.
In January 1998, an FDA advisory panel recommended approval of Dermagraft with the condition that Advanced Tissue Sciences, the company that manufactures Dermagraft, perform a post-marketing study to confirm efficacy and provide physician training. The FDA subsequently concluded that Dermagraft was not approvable without supportive data from an additional clinical trial.
Advanced Tissue Sciences recently announced the results of the interim analysis of data from the additional clinical trial. Data from the trial showed that Dermagraft was healing more ulcers than the control treatment at 12 weeks for all patients, and healed almost twice as many ulcers as the control treatment in diabetic foot ulcers having a duration of greater than six weeks.
Other therapies for the treatment of diabetic foot problems are on the horizon.
Michael I. Weintraub, MD, FACP, PC, chief of neurology at Phelps Memorial Hospital in North Tarrytown, New York, prescribes the use of magnets to alleviate the pain associated with diabetic neuropathy in the feet.
“Since the peripheral nervous system is magneto-sensitive, I speculate that constant magnetic stimulation possibly could reduce these uncomfortable symptoms,” says Weintraub, who conducted a study that was published in the January 1998 issue of the American Journal of Pain Management. In the study, eight people with diabetes and six subjects with peripheral neuropathy wore magnetic foot pad insoles for 24-hour periods for up to four months. The strength of these devices was 470 gals.
“Surprisingly, 75 percent of the people with diabetes and 50 percent of the non-diabetics showed improvement in foot pain,” says Weintraub.
Doctors in Britain have found that small injections of silicone under the metatarsal head of the foot can protect against callus formation and diabetic foot ulcers.
According to research presented last June at the ADA’s 59th Annual Scientific Sessions in San Diego, 28 patients received either injections of silicone in 1.5 ml. doses or a placebo under the metatarsal head where a callus had formed. Measurement of the callus thickness and plantar tissue were taken periodically over the course of one year.
After 12 months, plantar tissue thickness at the injection site had been reduced in 69 percent of the silicone group. After two years, some patients in the silicone group had lost their calluses at the injection sites.
“I don’t see any reason not to use silicon injections,” says Scheffler, “but it hasn’t been an approved treatment method and it’s not available, other than in clinical trials.”
Depending on the nature of the wound, Tarran cited ultrasound as possibly having therapeutic value in healing wounds.
“It is being used today as an adjunct and I am seeing some benefits,” he says. “The biophysical effects of ultrasound, if applied correctly, should be able to produce physiological changes that can accelerate wound healing and tissue repair. Why this all happens is still a bit of a mystery.”
Tarran adds that patients with foot ulcers would have to see a physical therapist and get a prescription for ultrasound therapy around the wound, but not directly on the wound.
“Around the edges of the wound for about five minutes a day,” he recommends.
Tarran also points out that whirlpool treatment is used
for diabetic foot wounds but has several drawbacks, including maceration, or softening, of the skin and further infection of the wound.
“It might not be the safest thing in the world,” says Tarran, “but it has been proven to debreed, or cleanse, the wound.”
According to the November 1998 issue of Diabetes Care, using maggots to treat diabetic foot wounds was found to be successful in 12 of 22 patients.
At Hebrew University in Jerusalem, 50 to 1,000 maggots, 24 to 48 hours old, were applied to the skin two to five times weekly and were then left on for 24 to 72 hours. They were then washed out of the wound.
Researchers concluded that “wound healing rates were faster in patients treated with maggot therapy than in patients receiving only conventional dressing.”
Editor’s Note: Diabetes Health encourages every person with diabetes to see a podiatrist at least once a year. Treatments like the ones featured here should never replace professional care, and you should always notify your doctors when you take a non-prescription treatment. Only a professional has the tools to assess the health of your feet.