In the VII Meeting of the Diabetic Foot Study Group,
which took place in Lucca (Italy) last September, we had
the chance of interviewing the professor of surgery Da-
vid G. Armstrong, DPM, PhD and director of Southern
Arizona Limb Salvage Alliance (SALSA) at the University
of Arizona College of Medicine.
Dr. Armstrong is one the most charismatic characters
worldwide as regards the diabetic foot. He has a myriad
of published papers. As we could find out he is very
agreeable and funny as well as being a top professional
of his field.
Good afternoon David,
What kind of orthopodological techniques do you use to treat patients with diabetic ulcers?
Our goal is to reduce pressure on the foot or to spread force out over a larger area. We can do that non-
surgically through certain types of casts or with shoes. If that is not enough, we can do it through surgical
means and we don’t look at it as a difference. We just see that if we can do it non-surgically then we will.
Because sometimes the best surgery is the one that we never did. There are many times when shoes are
not enough and we may have to do a procedure. So the most common procedures that we do are Achilles
tendon lengthening and forefoot reconstructions. The most common kinds of non-surgical interventions that
we have for prevention are special shoes which are molded to the foot.
Now we are very excited because there are types of insoles, some of which are here at the meeting this year,
which are very simple, very inexpensive but they can reduce sheer very well. These are very simple and
don’t require a lot of customization and yet they can work very well on the prevention side. Another thing that
seems to work very well is a very simple tool: and that is measuring skin temperature. A wound will heat up
before it breaks down. This is secondary to inflammation caused by repetitive stress. So if we can identify
that by whatever means then we can probably prevent a problem. Over many years now we have found that
skin temperatures “comparing” one foot to the other one. If one site is significantly warmer, then that would
suggest something potentially bad is happening and we can take action to modify activity or modify the shoes
or something. In the United States we have now three separate federally-sponsored clinical trials that sug-
gest that giving people simple thermometers to look at the feet is very effective at preventing ulcers. In fact
it is very much like a glucose meter for the foot. In this manner, people can dose the activity by checking the
temperature on their foot, just like they dose things when they are checking their glucose. So that is very ex-
citing as well.
Do people understand the way to use it?
This is a great question and the answer is yes. Remarkably, they do. I thought that people would not be com-
pliant with the thermometer, just like many times they don’t check their glucose. In fact, it is the opposite. So
we are working now with technologists in the U.S. but also in Spain to develop better thermometers for this
area. Some of them are like scales that you can step on and they will check it out for you and ultimately merge
it with telemedicine so it is very easy. It is very promising, as the future is here.
What do you think about the minimal surgery procedure for diabetic ulcers?
I think for major reconstructive surgery, I am not aware of a lot of data to support minimal incision foot sur-
gery. But, what I do know is that the type of surgery that we do on the Achilles tendon involves very small
incisions and that seems to work very well. So I think the answer to your question would be, if the surgeon
knows what he or she is doing and has a good philosophy then I think it doesn’t matter if you make a small
one or a big incision. It is the same philosophy to try to help the foot. So I think that would be the answer to
What is the staff structure in your diabetic foot unit and how many patients do you attend upon every
Our diabetic foot clinic adheres to what we have termed the “Toe and Flow” philosophy. Our SALSA team lies
within a vascular surgery service. I direct SALSA with my friend and colleague Professor Joseph Mills, who
is the Chief of Vascular and Endovascular Surgery at the University of Arizona.
We approach “acute” problems in this manner: If the problem is primarily vascular, the “flow” (vascular) part of
SALSA takes primacy. When it has been revascularized to be primarily neuropathic, then the “toe” (podiatric)
part of the team takes primacy to heal and then to prevent. We often, however, share patients in real time in
the operating theatre and on the wards when there is “marginal” flow. We have anywhere from 5 to 20 inpa-
tients on our service and see 400-500 patient visits per month in our clinic.
Do you have any effective schemes for prevention?
I think improvements in insoles, thermometry, and reconstructive surgery are areas that will see considerable
growth over the coming few years.
What projects are you currently working on?
We have some exciting work going on in a number of areas. We are doing National Institutes of Health (NIH)-
sponsored work in offloading devices that might be easier to use. We are also working with our Surgical
Transplant Unit and my friend and colleague Horacio Rilo on connective tissue transplantation. In between
those two points is a rich spectrum of projects about which we are very enthusiastic.