Limb Salvage
New Products, Technologies and Surgeries
Vickie R. Driver, MS, DpM, Clinic Director
Madigan Army Medical Center- Foot at Risk/Limb Salvage Clinic

The clinic combines clinical expertise with the latest technologies in diabetic foot care to achieve limb preservation. One such new product is used to treat MRSA, or Methicillin-Resistant Staphylococcus Aureus. In the past, most serious staph bacteria infections were treated with an antibiotic related to penicillin, but in recent decades treatment has become increasingly difficult because staph bacteria have become resistant to various antibiotics. But the clinic assistant said there are new treatment options for resistant bacteria like MRSA, including oral antibiotics that work as good or better than traditional at-home intravenous therapy.

Although at-home IV therapy and at-home nursing of patients can save Madigan money because such patients are out of the hospital, there are potential complications that go with it. "You run the problem of further infections due to continuous infusion," Dr. Driver said. "We conducted a study looking at a new oral antibiotic that treats resistant bacteria infections and it showed similar efficacy and safety to the IV product. The benefit of using an oral is that we eliminate the need for at-home nursing service. We eliminate the need for line-infusion IV therapy, which is a high risk for infection at the site of infusion. Additionally, they have to have chest x-rays to make sure the line is placed properly. They have to be at home during the day, every day two or three times a day. It is truly amazing we have at least an oral drug that can do this [instead]."

Dr. Driver said MRSA is becoming ever more common. "Part of the problem is that our patient population has had a fair amount of antibiotics along the way, so of course they've gotten resistance," she said. "Also, in certain instances if a clinic is not familiar with treating these kinds of wounds, they might guess that one is infected when in fact it isn't, so they've been given antibiotics but maybe they could have gone without [them]."

Dr. Driver said other new products are being used at the clinic to treat diabetic conditions. "We use a new system that is a vacuum device that sucks out the wound, because a lot of these wounds are infected and have lots of drainage, so it helps clean up the wound," she said.

The device consists of a sponge that is placed in the wound and is attached to a vacuum system that is contained in a small pack and can be carried on a waistband to provide continuous negative pressure to the wound. It cleans up the wound bed and it stimulates wound healing.

The clinic staff also are studying the use of a new ultrasound device to debride wounds more easily. "You will take a scalpel and actually clean [wounds] out because there are a lot of different types of tissue that can move into a wound and will kind of close it off, much like a garage door, and it won't heal," Dr. Driver said. "So on a weekly basis, we debride it with a scalpel, but we're also looking at another new modality, which is an ultrasound debrider where you actually wave this ultrasound wand over the wound and it cleans it out. It's very exciting. There is an ultrasound machine that we have that has three different wands, as well as some fluid that you attach so you actually place this wand in the wound that sprays fluid and also delivers ultrasound and it debrides the wound and it has the ability to tell bad tissue from good tissue. While we're doing a very good job at what we have, we are constantly looking for new ways to improve the healing of these wounds and solving the infections."

Skin equivalents are also being used and developed for wounds at the clinic. After a wound is cleaned and debrided, then such an equivalent would be placed on it with a dressing over it, much like a skin graft. "The benefit is we don't have to make a wound on these patients somewhere else, which means we save that whole spot to heal, as well," Dr. Driver advised. "We also use antibiotic beads in wounds that have infected bone. We mix them up [with cement] and we put them in the wound in the operating room, directly inside so that it leaches out the antibiotics for several days, and that saves the patient. You use it in conjunction with IV antibiotics or oral antibiotics, but it allows you to deliver more antibiotic to the wound itself where it's infected. We also are now using some absorbable beads and we've put antibiotics in those, so that you can actually close the wound right over it."

Platelet-derived growth factors made of topical gels are also used for diabetic neuropathy wounds. Some skin equivalents further have growth factors in them. "When a wound is chronic, you don't necessarily have all those new growth factors that can stimulate healing, so we put [them] into the wound," Dr. Driver said. "Where I'd love to see all this go is [to] someday have a dipstick that you would place in the wound and say, 'Okay, what does this wound need to heal? Does it need a growth factor? Does it need an antibiotic? What does it need?' We're not quite there yet, but we're all moving in that direction. It's promising. We'll see."

Furthermore, Dr. Driver said there is a new study protocol in the works that is aimed at preventing blisters in active duty Army cadets. "We look at the high-risk patient diabetic population, and we're also looking at preventing injuries in the military population," she said. "This is a new product being looked at that will be placed on the patient's skin before they go and have a very active day. There are some really severe training periods [for] our cadets. One of the most common problems is blister creation. [It] could put a person out of function for a while, so we're looking at ways to prevent the blisters."

Saving Limbs

The clinic often receives requests for consults on limb-saving procedures. "These types of surgeries are not done on a regular basis by very many surgeons," Dr. Driver said. "This is a skill that one would develop to save a limb, maybe take a part of the foot, but performing a procedure that would give them function, because diabetics cannot be stationary for very long or their blood-glucose will be elevated."

Amputations performed at the clinic have declined over the last three years. "When I first came here we would have morning rounds in the orthopedic department and we had what's called a 'stump doc', meaning that surgeon was responsible for all the amputations done for that period of time, and they would present the cases. Well, we have not had a 'stump doc' in this clinic since early 1997," Dr. Driver said. "We now at times have to send our orthopedic surgeons out to have a special training in amputations because we now do very few."

According to clinic staff, lower extremity amputations, which are amputations of the toes, partial foot or below the knee, at Madigan occurred less than 40 times in 2000, 20 times in 2001, and less than 20 times in 2002. Currently, Madigan has about 2,800 enrolled diabetic patients. According to the American Diabetes Association (ADA), more than 60 per cent of non-traumatic lower-limb amputations in the U.S. occur among people with diabetes, and from 1997-1999 about 82,000 such amputations were performed each year on diabetics. The ADA also reports that comprehensive foot care programs can reduce amputation rates by 45-85 per cent.

When asked for examples of patients whose limbs have been saved at the clinic, Dr. Driver cited a 22-year old female patient with spina bifida, a disease process that is similar to diabetes in which patients often are unable to feel their feet. "She was in Germany and she had an ulceration on her foot, two of them in fact, for almost two years, and prior to being brought to this clinic, they were going to amputate below her knee," Dr. Driver said. "Now being 22, she had an eight- or nine-month old, and she had a military husband, and they sought us out. We were able to identify what was causing the biomechanical problems, so were able to decrease the pressure on her foot that she couldn't feel. When she would walk she couldn't tell that she was getting a blister or a sore, so just healing the wound wasn't enough. We needed to create orthotics for her shoes and straighten her alignment. We took her to the operating room, we found that she had a bone infection, but we were able to resect a small part, transfer a tendon and we actually had her back on her feet within three months of the surgery, and she was back in shoes."

Dr. Driver said the clinic treated another woman in her 60s this year who had bilateral ulcerations on her heels and ankle bones, and who had been told that she needed bilateral amputations. "She was brought into this clinic, and I'm happy to say that her wounds are closed. That was seven months ago," Dr. Driver said. "Now, I don't think it's because we are any smarter than any other doctor out there. It is because we are dedicated to limb preservation. We can't save every one. There are some scenarios that there is just nothing you can do and it would not be in the best interest of the patient. But because we are very consistent, we are very dedicated and we are well-read and educated on the cutting edge modalities available, we are able to solve a lot of these problems."

Next Week, Feelings Lost and the Diabetes Scorecard

The clinic has hosted two interdisciplinary conferences on diabetes care in the past year and is sponsoring the NW Limb Preservation Conference, March 15-17 at Meydenbauer Center in Bellevue, Wash., on prevention of diabetic amputations with a focus on medicine, surgery, research and wound care. These conferences are attended by a very wide spectrum of physicians, from infectious disease docs to orthopedic, vascular, cardiac surgeons, wound care nurses, internists and endocrinologists," Dr. Driver said. "The last two that we have had have been 'train the trainers.

To learn more about the conference click here ( http://www.thegenevafoundation.org/events/NWLimb.html)

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