Introduction

Diabetic foot ulcers are among the most common complications of patients with diabetes mellitus with peripheral neuropathy that have not been properly managed or controlled. It is caused as a result of poor blood pressure control, diabetic neuropathy, peripheral neuropathy (being painless), or poor foot care. However, diabetic foot ulcer is quite preventable.

The annual incidence of diabetic foot ulcers worldwide is between 9.1 to 26.1 million. Around 15 to 25% of patients with diabetes mellitus will develop a diabetic foot ulcer during their lifetime. As the number of newly diagnosed diabetics is increasing yearly, the incidence of diabetic foot ulcers is also bound to increase.

What Causes Diabetic Foot Ulcer?

A diabetic foot ulcer is most commonly caused by:

• Peripheral Neuropathy: This is damage to the peripheral nerves (the nerves outside the brain and spinal cord that relay information between the brain and the rest of the body). When there is a level of high blood sugar, it damages these nerves, causing different degrees of numbness, tingling, or burning in the extremities such as the feet. For example, a person may acquire an injury such as a blister but not notice it due to not feeling pain in their feet. This may result in the wound not being treated, causing it to worsen and develop into an ulcer.
• Hyperglycemia: When the blood sugar level is high, it can affect and slow down the healing process of a foot ulcer. It can also increase the risk of conditions that affect the circulatory system, such as peripheral artery disease. These conditions can restrict blood flow and result in poor circulation, making the foot less able to heal and fight infections.
• Poor Blood Circulation - is a form of vascular disease in which blood doesn’t flow to the feet efficiently. Poor circulation can also make it more difficult for ulcers to heal.
• Irritated or Wounded Feet. Ulcers can be identified by drainage from the affected area and sometimes a noticeable lump that isn’t always painful.

Who is at Risk of Developing Diabetic Foot Ulcers?

Anyone with diabetes can develop foot ulcers, but it is more prevalent in people over the age of 45 years. People who use insulin are at a higher risk of developing a foot ulcer, as are patients with diabetes-related kidney, eye, and heart disease. Being obese and using alcohol and tobacco can also increase the risk of developing foot ulcers.

Also, poor foot hygiene (not washing regularly or thoroughly, or not drying the feet after washing); wearing poorly fitted or poor-quality shoes; and the improper trimming of toenails can make a diabetic person at risk of diabetic foot ulcer.

Are diabetic Foot Ulcers Contagious?

No, foot ulcers aren’t like other foot conditions that might be passed from person to person (contagious). A person cannot spread an ulcer to - or catch it from - someone else.

How Can Diabetic Foot Ulcers Be Recognized?

Diabetic foot ulcers are open wounds in the skin that are typically deep enough to see underlying tissues, sometimes even the bone. They can also take on almost any shape, for example, they might be shaped like a wedge or crater.

When an ulcer is starting to develop on the foot or toe, one may notice changes in the skin like:

• Dry skin
• Cracked skin
• Scaly skin
• Redness
• Rashes

Signs of foot ulcers are not always obvious. Sometimes, a patient won’t even show symptoms of ulcers until the ulcer has become infected. One of the first signs of a foot ulcer is drainage from the foot that might stain your socks or leak out in the shoe. Unusual swelling, irritation, redness, and odors from one or both feet are also common early symptoms. The most visible sign of a serious foot ulcer is black tissue (called eschar) surrounding the ulcer. This forms because of an absence of healthy blood flow to the area around the ulcer.

Partial or complete gangrene, which refers to tissue death due to infections, can appear around the ulcer. In this case, odorous discharge, pain, and numbness can occur.

How is Diabetic Foot Ulcer Diagnosed and Treated?

Once a person recognizes symptoms that seem like a foot ulcer condition, it is recommended to get diagnosed immediately. Foot ulcers in patients with diabetes should be diagnosed and treated for several reasons:

• To reduce the risk of infection and gangrene
• To improve function and quality of life

A doctor can diagnose if a patient has a diabetic ulcer and its severity through:

• Getting the medical history of the diabetic patient
• Knowing the blood sugar level management
• Understand the pre-existing complications of diabetes including sensory neuropathy
• History of peripheral vascular disease, callus, and its prior treatment and prognosis
• Examining the peripheral pulses of the feet
• Looking for anomalies around the feet, the presence of callus
• Signs of vascular insufficiency
• Location of the ulcer
• Check for the presence of scabs

Ulcers especially neuropathic ulcers are most common in the weight-bearing areas such as the plantar metatarsal head, heel, tips of hammer toes, and other prominent areas. Other physical features include hammertoes, brittle nails, calluses, and fissures. Vascular ulcers are found in the lower part of the foot.

To identify the progression of ulceration and which factors may contribute to its development, the Wagner classification can be used through staging. Diabetic foot ulcers can be staged as follows:

• Grade 0:Skin intact and undamaged, but the foot is at risk
• Grade 1:Superficial ulcer which means that the skin is broken but the wound is shallow (in the upper layers of the skin)
• Grade 2:Deeper ulcer wound
• Grade 3:Deeper tissue involvement, with abscess or osteomyelitis (part of the bone is becoming visible)
• Grade 4:The forefront of the foot (the section closest to the toes) has gangrene (necrosis).
• Grade 5:Extensive gangrene involving the entire foot

To find out precisely how deep the ulcer goes, and to see if it caused an infection in a nearby bone, these tests can be carried out:

• X-ray – This is used to look for any underlying osteomyelitis, the presence of air in the subcutaneous tissue, any signs of underlying fractures, and the presence of a foreign body.
• MRI – Once osteomyelitis is suspected, an MRI is the most preferred test used to confirm the presence of a diabetic foot ulcer.
• CT Scan

Treatment of Diabetic Foot Ulcer

The treatment of all foot ulcers begins with proper foot care. Inspecting the foot is very important, especially for people with diabetes. Treating foot ulcers early can help to prevent infection and keep the sore from getting worse.

The primary goal in the treatment of foot ulcers is to obtain healing as soon as possible. The faster the healing of the wound, the less chance for an infection. Treatment options for diabetic foot ulcers include:

Non-Surgery Options

• Off-Loading: This is reducing the pressure and irritation to the ulcer area to speed the healing process. Patients may be asked to wear special footwear, a brace, or specialized castings, or use a wheelchair or crutches.
• Managing One’s Blood Sugar Level: The utmost importance during the treatment of a diabetic foot ulcer is the management of a patient’s glucose level. This can help the feet to heal quickly.
• Dressings and Medications Application: Appropriate wound management includes the use of dressings and topically-applied medications. These range from normal saline to advanced products, such as growth factors, ulcer dressings, and skin substitutes which are highly effective in healing foot ulcers. Also, the doctor may prescribe antibiotics, antiplatelets, or anticlotting medications to treat the ulcer if the infection progresses even after preventive or anti-pressure treatments.
• Preventing Infection: Keeping blood glucose levels under tight control; keeping the ulcer clean and bandaged; daily wound dressings; and not walking barefooted are several important factors to keep an ulcer from becoming infected

Surgery Options

A majority of noninfected foot ulcers are treated without surgery; however, when this fails, surgical management may be appropriate.

• Debridement - One way to treat foot ulcer is debridement. This treatment removes dead skin and tissue. The skin surrounding the wound is cleaned and disinfected. The wound is probed with a metal instrument to see how deep it is and to see if there is any foreign material or object in the ulcer., cuts away the dead tissue, then washes out the ulcer. Other methods the doctor may use to remove dead or infected tissue are: putting the foot in a whirlpool bath; using a syringe and catheter (tube) to wash away dead tissue; applying wet to dry dressings to the area to pull off dead tissue; putting special chemicals, called enzymes, on the foot ulcer. These dissolve dead tissue from the wound.
• Shaving or excision of bone(s)
• Correction of various deformities, such as hammertoes, bunions, or bony “bumps.”
• Lengthening tendons
• Amputation

Amputation

Amputation is the surgical removal of all or part of a limb or extremity such as an arm, leg, foot, hand, toe, or finger. Amputation of the leg -- either above or below the knee is the most common amputation surgery.

Diabetes also can lower the amount of blood flow in the feet. Not having enough blood flowing to the legs and feet can make it hard for a sore or an infection to heal. Sometimes, a bad infection never heals. The infection might lead to gangrene. Gangrene and foot ulcers that do not get better with treatment can be treated with amputation of the toe, foot, or part of your leg.   This is known as lower extremity amputation

A surgeon may perform an amputation to prevent a bad infection from spreading to the rest of the body, and to save a life. Good foot care is very important to prevent serious infections and gangrene.

Why Is Amputation Needed?

An amputation may be needed for many reasons. The most common is poor circulation because of damage or narrowing of the arteries, called peripheral arterial disease. Without adequate blood flow, the body's cells cannot get oxygen and nutrients they need from the bloodstream. As a result, the affected tissue begins to die and infection may set in. For diabetic foot ulcer patients, it is needed when all treatment options fail to work. So, to save the lower extremity from a severe infection that could spread to other parts of the body, amputation is usually done. The surgeon removes the leg while keeping as much healthy bone, skin, blood vessels, and nerve tissue as possible.

Amputation Procedure

Except for emergency amputation, a diabetic foot ulcer patient needing amputation is usually assessed before surgery, to understand any factors that might affect the patient’s rehabilitation.

An amputation usually requires a hospital stay of five to 14 days or more, depending on the surgery and complications. The procedure itself may vary, depending on the limb or extremity being amputated and the patient's medical examination such as physical condition e.g., cardiovascular and respiratory system.

The doctor will also check the condition and function of the healthy limb. Removing one limb can place extra strain on the remaining limb, so it's important to look after the healthy limb.

It may also include a psychological assessment to determine how well one will cope with the psychological and emotional impact of amputation, and whether you'll need additional support. There may be an assessment of your home, work, and social environments to check if any changes will need to be made to help you cope.

You may also be introduced to a physiotherapist, who will be involved in your post-operative care. A prosthetist (a specialist in prosthetic limbs) will advise you about the type and function of prosthetic limbs or other devices available.

How Are Amputations Done?

Amputations can be done under a general anesthetic (where you're unconscious) or using either an epidural anesthetic or spinal anesthetic (both of which numb the lower half of the body). Most amputations involve removing a section of a limb rather than the entire limb. Once the section of the limb has been amputated, additional techniques can be used to help improve the function of the remaining part of the limb and reduce the risk of complications.

How Long Does It Takes to Recover from Amputation?

Recovery from amputation depends on the type of procedure and anesthesia used. In the hospital, the nurses change the dressings on the wound or teach the patient to change them. The doctor monitors wound healing and any conditions that might interfere with healing. The doctor prescribes medications to ease pain and help prevent infection, especially at the site of the operation which may be painful, so painkillers would be given to ease the pain.

If the patient has problems with phantom pain (a sense of pain in the amputated limb) or grief over the lost limb, the doctor will prescribe medication and/or counseling, as necessary.

Physical therapy, beginning with gentle, stretching exercises, often begins soon after surgery. Practice with the artificial limb may begin as soon as 10 to 14 days after surgery.

Ideally, the wound should fully heal in about four to eight weeks. But the physical and emotional adjustment to losing a limb can be a long process. Long-term recovery and rehabilitation will include:

• Exercises to improve muscle strength and control
• Activities to help restore the ability to carry out daily activities and promote independence
• Use of artificial limbs and assistive devices
• Emotional support, including counseling, to help with grief over the loss of the limb and adjustment to the new body image

Amputated Leg Replacement

After an amputation, you may be able to have a prosthetic limb fitted. Prosthetic limbs are not suitable for everyone who has had an amputation because an extensive course of physiotherapy and rehabilitation is required.

Adjusting to life with a prosthetic limb takes a considerable amount of energy because one has to compensate for the loss of muscle and bone in the amputated limb. This is why frail people or those with serious health conditions, such as heart disease, may not be suitable for prosthetic limbs.

If a patient can have a prosthetic limb, the type of limb that's recommended will depend on:

• the type of amputation the person just had
• the amount of muscle strength in the remaining section of the limb
• the patient’s general health
• tasks the prosthetic limb will be expected to perform
• whether the patient wants the limb to look as real as possible or is just concerned with its function

If it is thought that a patient would find it difficult to withstand the strain of using a prosthetic limb, a cosmetic limb may be recommended. This is a limb that looks like a real limb, but it cannot be used like a prosthetic limb. It is also possible to have a prosthetic limb that is both physically realistic and functional.

How to Prevent Diabetic Foot Ulcer

The best way to treat a diabetic foot ulcer is to prevent its development in the first place. Reducing additional risk factors, such as smoking, drinking alcohol, high cholesterol, and elevated blood glucose, exercising, and maintaining a healthy weight is important in the prevention and treatment of a diabetic foot ulcer. Wearing the appropriate shoes and socks will go a long way in reducing risks.

Learning how to check the feet is crucial in noticing a potential problem as early as possible. Inspect the feet every day - especially between the toes and the sole for cuts, bruises, cracks, blisters, redness, ulcers, and any sign of abnormality.

Foot Care

Foot ulcers and even amputation, are common complications of diabetic neuropathy. But one can prevent many of these problems by having a thorough foot exam at least once a year. Also having one’s doctor check the foot at every visit can help reduce the risk of getting foot ulcers.

To protect the health of the feet:

• Check The Feet Every Day: Look for blisters, cuts, bruises, cracked and peeling skin, redness, and swelling. Use a mirror or ask a friend or family member to help examine parts of the feet that are hard to see.
• Keep The Feet Clean and Dry:Wash the feet every day with lukewarm water and mild soap. Don't soak the feet. Dry the feet thoroughly.
• Moisturize Feet:This helps prevent cracking. But don't get lotion between the toes because it might encourage fungal growth.
• Trim Toenails Carefully -Cut toenails straight across. File the edges carefully so that they have smooth edges. If one can't do this oneself, ask a foot specialist to help out.
• Wear Clean, Dry Socks - Look for socks made of cotton or moisture-wicking fibers that don't have tight bands or thick seams.
• Wear Cushioned Shoes That Fit Well - Wear closed-toed shoes or slippers to protect the feet. Make sure the shoes fit properly.