Lower limb amputations are a huge source of illness, disability, and death for Americans living with diabetes. And these debilitating events are not uncommon, with a limb lost to diabetes every 20 seconds worldwide. The three most important factors for this are a compromised immune system (making it harder to fight infections), reduced nerve function (so there’s no pain when a problem develops), and reduced blood flow (which affects everything).
Diabetes can lead to various skin problems that all too often lead to the development of aggressive infections. For example, chronic pressure on a certain area of skin causes a thickening of the skin that most would simply call a callus. In the presence of diseased nerves in the feet (neuropathy), these chronic calluses will not harm. When there is reduced blood flow to the feet and toes, the skin and soft tissues will not be as healthy. Skin breakdown, what is technically tissue death, all too easily results from repeated stress on that tissue.
One of the most common places for these problems to develop is the tips of the toes. Digits are susceptible to changes in their positioning over the years, becoming angled up or down, even over adjacent fingers. This process can occur for many reasons. The decreased nerve function associated with diabetes can lead to hammertoes, when the muscles that keep the toes straight are no longer stimulated properly, a common product of diabetic neuropathy.
Hammer toes can also develop due to poor foot and leg mechanics. For example, the individual with an arch that rolls down too much is very common. This changes the pull of the muscles mentioned earlier, the ones that stabilize the fingers. Alternatively, hammer toes can develop with high arched feet, again due to an imbalance in the tendons and muscles that reach the toes.
Regardless of the cause of curled toes, this change in positioning usually results in excessive forces on certain areas of the toe on a regular, repetitive basis (such as daily). Initially, our skin reacts to this pressure by forming calluses, a natural and expected process. Our skin learns to improve the callus over time, a slow but progressive change. Predictably, this places more stress on the living, viable tissues beneath the callus.
Due to the blockage of their arteries, the tips of the toes are poorly supplied with the precious life-giving fluid that is blood. One of the consequences is reduced viability, i.e. the health of the soft tissues in this area. But the chronic pressure from the deformed toe further reduces the already impaired blood flow. Skin death is a common result, often at the end of the affected toe.
It is important to remember that these people have a reduced ability to feel certain sensations, such as the gradual stress on their skin from some toe deformity. Diabetic neuropathy may not be accompanied by specific symptoms. Most of those with neuropathy have no idea that they suffer from poor nerve function. If a specific study of different types of nerves is not performed, no one may be the wiser. Sufferers will continue to live with the belief that they will feel any developing skin lesions.
Although numerous interventions are possible before the development of skin breakdown, too many of these individuals are never properly evaluated. When a special diabetic foot assessment is performed, these changes are recognized and appropriate changes are made. When this targeted evaluation does not take place, historically, an excessive number of amputations results. Depending on many factors, diabetic shoes may be all that is needed, in which case it is beneficial because of the special material used for the inner sole. Different pads and pillows can also help reduce these stressors.
A surgical procedure can certainly be used to straighten the toes. This can be a risky endeavor, taxing the individual’s blood supply, which is often insufficient. Many diabetics are concerned about having this type of correction done, which leads to an increased risk of healing problems (more common in diabetics), risk of infection, and prolonged immobility.
A simple toe tendon release is underutilized. This can be achieved without an incision, a simple procedure done in the treatment room, with a needle. This can provide enough straightening of the toe to relieve the pressure. Not all hammers can be adjusted this way. But this simple one-minute procedure can sufficiently reverse the inexorable process of skin death, infection, hospitalization and amputation.
The procedure is called a digital tenotomy. Armed with an intimate knowledge of anatomy, it is a safe and reliable procedure. Due to the 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 Band-Aid. This can be an extremely satisfying procedure for the affected diabetes population.
For those who experience this event, major amputations (foot or leg) usually alter activity levels as well as cause circulatory imbalance, with death being the end product most of the time (within the next 5 years). But a measurable reduction in the number of major amputations is achievable. In diabetic foot medicine, it is said that 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 decline in nerve function, they will assume that the absence of pain indicates a minor problem. As the reader is informed, this is usually not the case. Bacterial invasion of the tips of the toes often leads to bone infection or spread of the bacteria up the tendons into the deeper spaces of the foot. Affecting 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 foot care at home. Hammertoes develop in many Americans and cause minimal problems for some. For someone with neuropathy and reduced circulation, these can start a deadly chain of events. It all starts with a bent toe. For many diabetics, a simple in-office procedure can prevent this cascade. We need to do more for our diabetics. We know how to prevent many of these unfortunate diabetic amputations. As a health system, we have yet to do that.
EDITORS’ NOTE Dr. Conway McLean is: a podiatrist now practicing foot and ankle care in the Upper Peninsula after taking over Dr. Ken Tabor’s practice. McLean has lectured internationally in surgery and wound care and is board certified in both, with a subspecialty in orthopedic foot therapy. Dr. McLean welcomes questions, comments and suggestions at [email protected]