Diabetic Foot Conditions
An estimated 23.6 million Americans have diabetes and some 750,000 new cases are diagnosed every year, according to the American Diabetes Association (ADA). The most common form of the disease, Type 2 diabetes, accounts for 90 to 95 percent of the cases and is caused by the body’s resistance to insulin at the cellular level and a relative insulin deficiency. Also known as adult-onset diabetes, the disease is nearing epidemic proportions due to an increased number of older Americans and a greater prevalence of obesity and sedentary lifestyles.
A number of systemic disorders occur from diabetes, including sensory neuropathy, a common complication of the disease in which patients lose nerve sensation. As a result, they lose feeling at the bottom of the feet and are unable to react to pain, pressure and heat. Another complication of diabetes affecting the foot is compromised circulation. Poor circulation to the feet can cause foot ulcers and prevent timely healing of wounds and injuries in the patient with diabetes.
According to published studies, 15 percent of Americans afflicted with diabetes, will develop a serious foot ulcer during their lifetime. Repetitive trauma or pressure that goes unnoticed due to sensory neuropathy can produce calluses that, without proper attention, eventually progress to ulcers. Chronic ulcers can become seriously infected if they are unnoticed or untreated. As a result, some 80,000 foot amputations are performed every year in the U.S. on patients with diabetes.
Early detection of risk factors associated with ulcer formation, therefore, is essential in the overall management of diabetic patients and can significantly reduce the incidence of ulcers and eventual amputation. Prompt and aggressive treatment of foot ulcers can prevent worsening and help accelerate healing. Diligent self care also is a key component for early detection.
Diabetic patients should inspect their feet every day, wear shoes that fit properly and minimize pressure, and maintain their blood glucose levels within the desired range. Regular visits to a foot and ankle surgeon for removal of calluses and ingrown toenails provide an opportunity to reinforce self-care behavior and detect new or impending foot problems. Diabetic patients should not try to remove calluses by themselves.
Patients with a long patient history of diabetes may experience change to their foot such as limited joint mobility, muscle atrophy and diminished fat padding that contribute to foot deformities and foot ulcers. For example, diabetes-induced atrophy of the muscles in the foot increases pressure at the tips of the toes and can cause a hammertoe deformity. The resulting constant pressure on the toes makes them susceptible to ulcers.
Foot deformities can also be the result of Charcot foot. Charcot foot typically occurs I diabetic patients with neuropathy. As a result of peripheral neuropathy, patients are unable to feel pain, resulting in joint injury with subsequent collapse. The first symptoms of Charcot include a warm, red, swollen foot that is sometimes painful. As the process progresses, microfractures of the bones in the foot and join collapse, resulting in a foot that is flattened, wider and sometimes deformed in a “rocker-bottom” fashion.
Off-loading techniques using orthotics and special shoes can help minimize pressure and prevent calluses. The pressure reduction approach also can prevent or minimize the risk of the foot ulcers that result from the abnormal, repetitive pressures caused by the foot deformities that are a complication of diabetes.
For treatment of the Charcot deformity, several months of non-weight-bearing cast immobilization is recommended to protect the foot from further structural collapse and deformity. Walkers, rigid weight bearing leg braces and custom orthotic insoles also are effective for maintaining the desired non-weight-bearing regimen.
In some cases, however, surgery may be the best option to relieve ulcer-causing pressure from Charcot foot. An ostectomy procedure to decompress foot ulcers is an effective conservative surgical option. A more intensive procedure involves surgical restructuring of the foot to realign and fuse it in a more anatomic position.
For patients with chronic foot ulcers, promising new treatments are becoming available to improve long-term outcomes. One example is bioengineered human tissue that has been used successfully in clinical trials to heal foot ulcers. The implantation of the bioengineered human tissue -- produced by seeding human skin cells onto an absorbable mesh -- supplies growth factors and structural proteins conducive to wound healing. The tissue is grown under controlled conditions and frozen. The treating clinician applies it to the prepared ulcer bed and covers the area with a dressing that provides a moist environment.
Optimal care of chronic foot ulcers also requires supportive home and work environments that allow patients to be compliant with an off-loading treatment regimen. This must be combined with appropriate glucose control through diet and medication, aggressive wound care, adequate treatment of infection, and use of custom-fitted shoe gear and orthotics to prevent reoccurrence of these ulcers.