How Does Diabetes Affect Feet?
Diabetes can cause serious foot problems, including the loss of nerve function (diabetic neuropathy). Diabetic foot problems can lead to:
- Diabetic foot ulcers: wounds that do not heal
- Infections: skin infections (cellulitis), bone infections (osteomyelitis) and pus collections (abscesses)
- Charcot arthropathy: fractures and dislocations
that may result in severe deformities
- Amputation: partial foot,
whole foot, or below-knee amputation
Symptoms of neuropathy include the loss of sensation or pain and tingling sensations. Because of the lack of sensation, patients may develop a blister, abrasion, or wound, but not feel any pain. Skin discoloration, skin temperature changes, or pain are
also common. Depending on the specific problem, patients may notice swelling, discoloration (red, blue, gray, or white skin), red streaks, increased warmth or coolness, injury with no or minimal pain, a wound with or without drainage, staining on
socks, tingling pain, or deformity. Patients with infection may have fever, chills, shakes, redness, or drainage. If the infection spreads to the blood stream, loss of blood sugar control or shock (unstable blood pressure, confusion, and delirium)
may occur. These can be serious life-threatening issues and require immediate medical attention.
Neuropathy is associated with the metabolic abnormalities of diabetes. Vascular disease is present in many patients at the time of diagnosis of diabetes. Ulcers may be caused by external pressure or rubbing from a poorly fitting shoe, an injury from walking
barefoot, or a foreign object in the shoe (rough seam, stone, or tack). Infections usually are caused by bacteria entering through a break in the skin such as an ulcer, area of toenail pressure, ingrown toenail, or areas of skin degeneration between the bases of the toes.
Nerve function may be abnormal, so the patient may not feel pain. This frequently causes a delay in the diagnosis, and the patient may be diagnosed late with a limb- or life-threatening infection as a result.
Your foot and ankle orthopaedic surgeon will make a diagnosis based
on the symptoms and signs noted above. The absence of sensation may be confirmed, and images may show air in the soft tissues, soft tissue swelling or defect, or changes consistent with bone infection, fracture, or dislocation.
Additional imaging studies may be helpful, including a bone scan, MRI, or CT scan. Tissue cultures may be obtained if any wounds are present. Vascular studies may help determine how well blood is circulating, which is important for predicting wound healing.
The goals of diabetic foot care are to have a foot that has good bony stability, fits inside of a shoe, and does not have any wounds.
Wounds may be cleaned and treated with dressings and immobilization devices such as custom boots or custom molded casts. Antibiotics may be given if necessary. Non-surgical treatment for Charcot arthropathy may include immobilization with or without weightbearing.
An infection such as an abscess or osteomyelitis may be treated surgically, by removing the decaying tissue. If the infection is severe, it may lead to amputation of part of the foot or leg.
Surgical treatment for Charcot arthropathy may include correction of the deformity with operative stabilization. If present, poor blood flow may be treated by vascular surgeons with arterial bypass procedures.
Close follow-up of patients with diabetic foot problems is needed because recovery may deteriorate despite minimal warning symptoms. Prolonged recovery times are common. Ulcer healing may require several weeks or months depending on the size and location
of the wound, adequacy of circulation, and patient compliance. Severe infections may result in partial foot or below-knee amputation.
Risks and Complications
Diabetic foot wounds may lead to deeper infection, pus collections (abscesses), and bone infection. Patients often do not realize they have an infections because of the loss of normal sensation. The delay in seeking treatment leads to a very high rate
of amputation (partial foot,
whole foot, or below-knee).
Your surgeon will only perform an amputation if it is necessary to prevent the infection from spreading further and becoming life threatening.
How frequently should I examine my own feet?
Examine your feet several times daily, before putting on shoes, and after removing shoes. A mirror on the floor (like you may see at a shoe store) may be helpful. If self-examination is not possible, a family member or caregiver may be trained in daily foot
Self-examination should include inspection for signs of pressure (redness, whiteness of skin, or other discoloration) or skin breakdown on all skin surfaces including the spaces between the toes and edges of toenails.
How frequently should my feet be examined by a healthcare provider?
If you have neuropathy, vascular disease, or deformity, you should be examined by a foot and ankle orthopaedic surgeon every 1-2 months. If you do not have neuropathy, vascular disease, or deformity, see your doctor once per year for an exam
How frequently should I see my surgeon if I'm being treated with a total contact cast for a foot ulcer?
After the first cast is applied, the follow-up examination is within one week. Subsequent follow-up is every 1-2o weeks. Any unusual symptoms should be reported to the doctor's office immediately, including a feeling of tightness or looseness
of the cast, soreness, pain, foul odor, fever, red streaks, or breakdown of the cast.
What type of shoes should I wear if I have neuropathy?
Comfortable, well-fitting shoes are important to help prevent ulcers and wounds in diabetic, neuropathic feet. If no deformity is present, prefabricated shoes may be appropriate. If there is deformity from Charcot arthropathy, custom inserts, bracing, or shoes may be prescribed.
Contributors/Reviewers: Zachary Vaupel, MD; David Macias, MD
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