Lower limb amputations are a tremendous source of illness, disability, and death for Americans living with diabetes. And these debilitating events are not a rarity, with a limb lost to diabetes every 20 seconds worldwide. The three main factors in this are a weakened immune system (which makes it difficult to fight infections), reduced nerve function (so there is no pain when a problem develops), and reduced blood flow (which affects everything).
Diabetes can lead to a variety of skin problems, which too often lead to the development of aggressive infections. For example, chronic pressure on a specific area of the skin causes thickening of the skin, which most would simply refer to as a callus. In the presence of the diseased nerves in the feet (neuropathy), this chronic callus will not hurt. When there is reduced blood flow to the feet and toes, the skin and soft tissue will not be as healthy. Skin breakdown, which is technically tissue death, results too easily from repetitive stress on this tissue.
One of the most common places where these problems develop is at the tips of the toes. The digits are susceptible to changes in their positioning over the years, becoming slanted up or down, even across adjacent toes. This process can happen for several reasons. The reduced nerve function associated with diabetes can lead to hammertoes when the muscles that keep the toe straight are no longer properly stimulated, a frequent product of diabetic neuropathy.
Hammertoe can also develop as a result of poor foot and leg mechanics. For example, very common is the individual with a bow that rolls off too much. This changes the pulling power of those muscles mentioned before, those that stabilize the digits. Alternatively, hammertoes can develop in the high arched foot type, again due to an imbalance in the tendons and muscles that extend to the toes.
Regardless of the cause for the contracted digits, this change in positioning typically results in excessive forces on a certain area of the toe on a regular, repetitive basis (such as daily). Initially, our skin responds to this pressure by callus, a natural and expected process. Our skin learns to make calluses better over time, a slow but progressive change. Predictably, this results in a greater burden on the living, viable tissues beneath the callus.
Due to blockage of their veins, the tips of the toes tend to be poorly supplied with the precious life-giving fluid that is blood. One consequence is reduced viability, ie health, of the soft tissue in this area. But the chronic pressure of the deformed toe further reduces the already impaired blood flow. Skin death is a common consequence, often at the end of the affected toe.
It is critical to remember that these individuals have a reduced ability to feel certain sensations, such as the gradual tension on their skin due to some toe deformity. No specific symptoms may accompany diabetic neuropathy. The majority of those with neuropathy have no idea that they suffer from poor nerve function. If specific tests of different types of nerves are not performed, no one may be the wiser. The affected will continue to live with the belief that they will feel any developing skin injury.
Although numerous interventions are possible before the development of skin breakdown, too many of these individuals are never properly evaluated. When a dedicated diabetic foot evaluation is performed, these changes are recognized and the appropriate changes are made. When this focused assessment does not occur, a disproportionate number of amputations have historically resulted. Depending on many factors, diabetic shoes may be all that is needed, in this case beneficial due to the specialized material used for the insole. Various pillows and cushions can also help reduce these stressors.
Certainly, a surgical procedure can be used to straighten the toes. This can be a risky undertaking, taxing the individual’s blood supply, which is often inadequate. Many diabetics fear having this type of correction performed, which carries increased risks of problems with healing (more common in diabetics), risks of infection and prolonged immobility.
Underutilized is the simple release of a hamstring. This can be achieved without an incision, a simple procedure, carried out in the treatment room, with a needle stick. This can provide enough correction of the digit to relieve the pressure. Not all hammertoes can be fixed this way. But this simple one-minute procedure can sufficiently alter the inexorable process of skin death, infection, hospitalization and amputation.
The procedure is called a digital tenotomy. Armed with an intimate knowledge of the anatomy, it is a safe and reliable procedure. With its lack of soft tissue trauma, and the fact that it is performed without an actual incision, complications are rare. No stitches are needed. It’s a simple needle stick that requires little more than a plaster. This can be a very satisfactory procedure in the diabetic population so affected.
For those who experience this event, major amputations (a foot or leg), typically change activity levels, as well as a circulatory imbalance, with death the end product most of the time (in the subsequent 5 years). But a measurable reduction in the number of major amputations is achievable. In diabetic podiatry, the saying is, by saving a limb, we save a life.
Unfortunately, too many diabetics are never informed of these inexorable changes. If someone is not educated about the reduction in nerve function, they will assume that the lack of pain indicates an insignificant problem. As the reader has been informed, this is usually not the case. Bacterial invasion at the tips of the toes will often lead to bone infection or spread of the bacteria through the tendons into the deeper spaces of the foot. The involvement of this compartment in the foot has a poor prognosis.
The best medicine is prevention. Everyone with diabetes should be evaluated for their risk factors, as well as educated about proper diabetic home foot care. Hammertoes develop in many Americans and cause minimal problems for some. For someone with neuropathy and reduced circulation, they can start a deadly chain of events. Everything starts with a bent toe. For many diabetics, a simple office procedure can prevent this cascade. We must do better for our diabetics. We know how to prevent many of these unfortunate diabetic amputations. As a health care system, we have yet to do this.
EDITOR’S NOTE Dr. Conway McLean is: a podiatric physician now practicing foot and ankle medicine in the Upper Peninsula, after taking over the practice of dr. Ken Tabor accepted. McLean has lectured internationally on surgery and wound care, and is board certified in both, with a sub-specialty in foot orthotic therapy. Dr. McLean welcomes questions, comments and suggestions at firstname.lastname@example.org.