Diabetic Foot

Introduction

Foot problems are a common complication of Diabetes. Diabetes is a disease that affects how the body uses glucose, a sugar that is a source of fuel for the body. Normally, insulin, a hormone, helps glucose get into the body cells so that it is used for energy. People with diabetes either do not produce enough insulin or the insulin does not work like it should. Therefore, glucose does not get into the body cells. As a result, there is too much sugar in the blood, which can make people ill and result in medical complications. Diabetes is manageable. People with diabetes need to be aware of the possible associated medical problems.

Diabetes-related foot problems are most frequently caused by nerve damage and poor blood circulation. Infections, ulcers or sores, deformities, and trauma can all be the result. Foot problems are the leading reason for diabetes-related hospitalization. Further, diabetes is the leading cause of lower leg and foot amputation. Technology, research, and most importantly, diligence by individuals with diabetes can greatly improve the management of diabetes and reduce the risk of foot complications.

Anatomy

Your foot is a complex structure. It contains 28 bones that form 25 joints. The foot is divided into three regions: the forefoot, midfoot, and hindfoot. The hindfoot contains your calcaneus bone or heel. The forefoot contains your toes. Your toes are composed of small bones called phalanges. Your forefoot and midfoot bones, along with muscles and ligaments, form the arches in your foot.

Arches are important for absorbing shock and balancing your body. Your forefoot is a source of mobility. You push off the ground with your forefoot whenever you take a step. Your foot also bears the weight of your body and provides a base of support.

Nerves transmit impulses or messages between your foot and brain about sensation, positioning, and movement. Your circulatory system supplies blood to keep your foot structures healthy. Like the rest of your body, your feet are covered with skin. The skin on the sole or bottom of your foot is thicker than the skin on the dorsal or upper side of your foot.

Causes

The feet are very vulnerable to diabetes-related complications. Further, there are a variety of foot problems that can occur. Diabetes-related foot conditions are most frequently caused by poor blood circulation, infection, and nerve damage that can result in ulcers or sores, deformities, and trauma.

Diabetes can often lead to nerve damage called peripheral neuropathy. Peripheral neuropathy is a condition in which nerve function deteriorates in the limbs. This leads to a gradual loss of feeling in the hands, arms, legs, and feet. This is often problematic because pain is what enables you to know when something is wrong. Without pain, you may not realize that you have bruises, cuts, blisters or burns and seek medical treatment. It is important that people with diabetes receive medical treatment for foot sores because diabetes-related circulation problems can lead to more problems.

Peripheral vascular disease is a common diabetes-related circulation disorder. Poor circulation results in reduced blood flow to the feet. It can restrict the delivery of oxygen and nutrients that are required for normal wound maintenance and repair. As a result, foot injuries, infections, and ulcers may heal slowly or poorly. Minor skin problems on the feet can become worse and lead to infection.

People with diabetes are generally more prone to infections than people without diabetes. Wounds and injuries can be difficult to heal if diabetes is uncontrolled. This can be especially true of wounds in the feet. Infections tend to get worse or remain undetected, especially in the presence of diabetic neuropathy or vascular disease. Neuropathy can cause you to be unaware of wounds. Additionally, the increased pressure from the feet carrying the body weight aggravates foot wounds. Further, shoes can cause skin friction, rubbing, and tearing. The hot moist environment of shoes is favorable to infection and foot ulcers. Foot ulcers are sores caused by skin breakdown exacerbated by infection. Foot ulcers tend to develop over areas of high pressure, such as bony prominences or foot deformities.

Foot deformities are another common problem associated with diabetes. They occur when the ligaments and muscles that stabilize the foot bones deteriorate. This can cause the bones to shift out of position or for a series of bones that make up an arch to collapse. A hammertoe deformity is a common condition that occurs most frequently in the second toe, although it can be present in more than one toe. Increased pressure on the tips of the phalanges and the lack of muscle stability causes a joint in the toe to become permanently flexed with a claw-like appearance. The toe deformity and pressure displacement makes the toe susceptible to skin ulcers.

Charcot foot is another common foot deformity associated with diabetic neurogenic arthropathy. Neurogenic arthropathy is a progressive degenerative arthritis that results from nerve damage. Charcot foot most frequently affects the metatarsal and tarsal bones located in the midfoot and forefoot.

Charcot foot causes the foot muscles, ligaments, and joints to degenerate or break down. Without support, the foot becomes deformed. Without joint stability, the foot becomes unstable making walking difficult. Inflammation and pressure eventually can cause bone dislocation. The arches in the foot can collapse creating a rocker-bottom appearance.

People with Charcot foot have impaired or absent abilities to feel pain, temperature, and trauma. They may not be able to sense the position that their foot is in. This makes them vulnerable to injury, such as fractures, sprains, joint dislocation, bone erosion, cartilage damage, and foot deformity. They may even continue to walk on a broken bone without knowing it, because they cannot feel it.

Diagnosis

Your doctor can diagnose diabetic foot problems with a physical examination. Your doctor will ask you about your symptoms. There are a variety of tests your doctor may use to diagnose a problem with your foot. Testing is individualized depending on your symptoms and examination findings. Some of the most common assessments are described below.

Non-invasive vascular tests can provide information about the blood circulation in your feet. Your doctor can measure the amount of oxygen in your blood with a transcutaneous oxygen measurement. Your doctor will simply place sticky patches on your skin for this assessment. The blood pressure in your arm and ankle can be compared using the ankle-brachial index (ABI).

Another common assessment used during a foot exam is sensitivity testing. Nylon monofilament testing is useful to determine the degree of sensation in your foot. The test does not hurt. Your doctor will simply place the tip of a very thin piece of nylon, similar to a plastic thread, against the skin of your foot. Your doctor will test your foot in various places and alter the thickness of the filament. You will tell your doctor when you feel the filament touch your skin. A similar procedure using wands of random temperatures can be used to determine to what degree you can feel hot or cold temperatures.

In most cases, imaging tests are ordered to identify fractures, degeneration, and deformities. An X-ray may be ordered to show the type and location of your fracture. Some fractures, such as stress fractures, may not show up on an X-ray. In such cases, Computed Tomography (CT) scans or Magnetic Resonance Imaging (MRI) scans may be used to take a more detailed look at your bones. X-rays, CT scans, and MRI scans are painless procedures.

Your doctor may order an angiography to see the condition of the blood vessels in the legs and feet. An angiogram is a type of X-ray for the blood vessels. You will receive a small harmless injection of a radioactive substance that will highlight the blood vessels on the X-ray image.

A bone scan is useful for identifying bone abnormalities that are often associated with diabetes. A bone scan may show fractures, tumors, infection, and bone deterioration. A bone scan requires that you receive a small harmless injection of a radioactive substance. The substance collects in areas where the bone is breaking down or repairing. Further, three-phase bone scans and radiolabeled leukocyte scans are tests for determining the presence of infection.

Wound classification is very important for the treatment of diabetic-related ulcers. If you have an ulcer, your doctor will grade its progression with a diabetic foot or wound classification system. A wound is classified based on its stage of formation, from being visible on the skin to penetrating through the skin and to the bone. Additionally, your doctor may order sensitivity testing and wound cultures to identify or rule out infection.

Treatment

Overall, people with diabetes must monitor their blood glucose levels carefully, eat a balanced diet, exercise regularly, and see a physician routinely to prevent and stay on top of any problems that might develop. There are several options for diabetes-related foot problems. Treatment is individualized. It will depend on the source and severity of your foot problem. Your doctor will discuss appropriate treatment options with you.

Non-surgical treatments for diabetes-related foot problems include splinting, casting, or bracing to correct bone deformities. Your doctor can recommend proper footwear to provide structure and improve blood circulation. This may include a custom-walking boot. Your doctor can also provide medications or treatments for infections and skin ulcers.

Surgery

The main goal of treatment is to improve the integrity of the foot and reduce the risk of surgery and amputation. Surgery is considered for deformities that are too severe for a brace or shoe. Surgery may also be required to resolve advanced skin ulcers. In extreme cases, surgical amputation of the toes, foot, or leg is required to prevent further health problems and protect the remaining limb.

Recovery

Recovery from diabetes-related foot problems is different for everyone. It depends on the type of problem you experienced and the type of treatment you received. Because diabetes-related foot problems can be progressive, it is extremely important that you reduce your risk of complications and amputation by following preventive measures.

Prevention

The following are tips to help prevent diabetes-related foot problems:
• Monitor your blood glucose levels carefully, eat a balanced diet, and exercise regularly. See a physician regularly to prevent and stay on top of any problems that might develop.
• Inspect your feet daily. Examine your feet for redness, warmth, blisters, ulcers, scratches, cuts, and nail problems. Feel for hard or dry skin. Look at the bottoms of your feet and between your toes. Use a mirror or have someone else look for you to check the bottom of your feet for redness or cracking.
• Examine the inside of your shoes for foreign objects, protruding nails, and rough spots before putting them on.
• Have custom-molded orthotics or shoes made by a foot specialist. The special footwear can help prevent ulcerations and infections in the feet.
• Buy shoes late in the day and never buy shoes that need "breaking in." Shoes should be comfortable the minute you put them on. Select shoes with deep toe boxes and made of leather upper material. Do not wear new shoes for more than two hours at a time and do not wear the same shoes every day.
• Contact your foot doctor immediately if you experience ANY injury to your foot or if you notice any changes in your feet. Even a minor injury is important for a person with diabetes.
• Do not file down, shave or remove calluses or corns yourself. This should ONLY be done by a foot specialist.
• DO NOT SMOKE! It decreases the blood supply to your feet. • Ask your doctor about precautions for soaking your feet.
• Do not trim your own toenails. Your foot specialist should do this.
• Do not use any strong antiseptic solutions on your feet. Iodine, salicylic acid, and corn or callus removers can be dangerous.
• Do not wear socks or stockings with tight elastic backs and never use garters. Do not wear any socks with holes and always wear shoes with socks.
• You should never use any type of sticky product such as tape or corn plasters on your feet. They can tear your skin.
• In the winter, wear warm socks and protective footwear. Avoid getting your feet wet in the snow and rain and avoid letting your toes get cold.
• Keep feet away from heat--hot water bottles, heating blankets, radiators, and heating pads. Burns can occur without your knowledge. Water temperature should always be less than 92 degrees. Estimate the water temperature with your elbow or bath thermometer.
• Lubricate your entire foot if your skin is dry but avoid putting cream between your toes.
• NEVER walk barefoot.