Diabetic Foot Wounds

Diabetic foot wounds are one of the most common problems we see at the wound center. They are also one of the more common causes of hospitalization for diabetic patients and, tragically, they remain the leading cause of amputation.

It doesn’t have to be that way. With proper understanding of how problems come up and appropriate preventive measures diabetics can avoid foot problems. Here’s what you need to know.

Several factors contribute to the development of a foot wound in someone with diabetes. The major factor is the development of a neuropathy. Neuropathy simply means injury to the nerves preventing them from working properly. Neuropathies have many causes, but diabetes is the main one.

Neuropathy leads to wounds and sores for a couple of reasons. First, there is loss of protective sensation.  While no one likes the idea of experiencing pain, it does serve a useful purpose. It let’s us know if we’re doing something that’s damaging. Without the warning that something hurts, we can continue to do damage.

We see examples of this all the time. One fellow I saw was a construction worker. He stepped on a nail at work. It went right through his boot into his foot. He didn’t realize there was any problem until that night when he went to take his boot. He had spent all day walking with a nail stuck deep into his foot and never knew it. By that time it had caused quite a bit of damage. Fortunately, he responded well to treatment and eventually healed completely. But it makes the point about what can happen when you lose protective sensation. In times past, that fellow could well have lost his leg.

Another way neuropathy leads to foot problems is by damage to the nerves supplying the small muscles in the foot. If these muscles aren’t working properly to support the foot structure, bones can slide out of their normal positions. This creates pressure points over bony prominences that are easy to injure. Also, the deformity of the foot makes it more difficult to get properly fitting shoes.

Foe these reasons, a callus on the foot in a diabetic is a red flag. Calluses indicate pressure. As I say at the clinic “If you work in the garden, you get calluses on your palms, not on the back of your hands.”  I point this out because some people seem to think calluses “grow” on their own. They don’t. A callus is a protective thickening in the skin that arises in response to friction and pressure.

However, there’s a limit to how much protection a callus can offer.  Excessive pressure can damage the underlying tissue despite the callus. If you have normal sensation, you don’t do damage because it hurts and you stop doing whatever it was you were doing.

With a neuropathy, that doesn’t happen. There’s no warning pain so the damage continues.

A foot problem can develop anywhere, but one of the more common places for it to happen with diabetic neuropathy is on the ball of the foot at the base of the first or second toe.

A typical story goes something like this. A diabetic might notice they have a callous over that area but it doesn’t hurt and doesn’t look too bad so they don’t do anything about it. They go about their normal activities until one of two things happens: the foot blows up with an obvious infection or the callus suddenly breaks open to reveal an ulcer that goes all the way to the to the bone with lots of destruction of soft tissue.

The person often says the problem came up “overnight”. It didn’t. The thickened callous hid an underlying problem that was developing for some time. In fact, the thickened callus sealed off the area of injury until it reached the point of getting infected or the damage became so extensive the callus broke down.

Treatment of these wounds varies with the individual but always includes good local wound care, control of the diabetes, treatment of any infection, making certain there is good blood flow to the foot and, perhaps most importantly, protection of the wound from any pressure.

There are many different kinds of protective shoes and boots a person can use to do this. These may be adequate for relatively minor wounds (not that any foot wound in a diabetic is minor).  For more serious situations, a specialized cast has proven to be the most effective way to protect the foot and remove pressure from the area of the wound. This cast is a “total contact cast” and differs considerably from the type of cast typically used by orthopedic surgeons to treat broken bones. You can go to the page on total contact cast to find out more about it.

Other treatments include various advanced wound dressings, cultured skin grown in a lab, allografts and others. For serious situations, hyperbaric oxygen treatments can be limb-saving.

The bottom line is, we have a wide variety of tools available and can successfully treat the great majority of diabetic foot wounds. It’s still a very serious problem but the results are much better today than they were just a decade of so ago.

Even so, the best policy is prevention so be sure to check out the page on diabetic foot care.