NDEP | National Diabetes Education Program

Early manifestations of diabetes may present initially in the foot. Foot symptoms increase the risk for co-morbid complications, of which non-traumatic lower-extremity amputations (LEAs) are the greatest concern. According to 1997 hospital discharge data, diabetes accounted for approximately 87,720 LEAs in the United States, fully 67% of all LEAs (31). Between 1980 and 2001, the number of diabetes-related hospital discharges with LEA increased from an average of 33,000 to 82,000 per year (32).

LEA rates were highest among men, non-Hispanics/Latinos, African Americans, and the elderly. In 2003, there were about 75,000 diabetes-related hospital discharges with LEA. The LEA rate per 1,000 persons with diabetes that year was 3.9 among persons aged less than 65 years, 6.6 among persons aged 65–74 years, and 7.9 among persons aged 75 years or older.
One study found that 80% of non-traumatic LEAs are preceded by a foot ulceration, which provides a portal for infection (33). According to Behavioral Risk Factor Surveillance Study (BRFSS) data, approximately 12% of U.S. adults with diabetes had a history of foot ulcer, a risk factor for LEA (34). Another report identified minor trauma, ulceration, and faulty wound healing as precursors to 73% of LEAs, often in combination with gangrene and infection (37). Other risk factors include the presence of sensory peripheral neuropathy, altered biomechanics, elevated pressure on the sole of the foot, and limited joint mobility (35).

The Charcot Foot

Patients with neuropathy are at risk for painless degenerative arthropathy that typically affects the tarsometatarsal and metatarsophalangeal joints, resulting in a red, swollen, and possibly deformed foot that can be mistaken for cellulitis. Radiographs may show collapse of joint structure, and can be misinterpreted as osteomyelitis. Treatment for Charcot arthropathy, however, is not antibiotics but a non-weight-bearing cast (once any acute edema has resolved) and special shoes to correct altered biomechanics. Without proper treatment, the Charcot foot can progress to further deformity, ulceration and lead ultimately to amputation.

Consider it a “red flag” when a patient complains that his shoes no longer fit, or is wearing slippers or shoes with sections cut out to accommodate changes in foot shape, or walks with a new limp. A Charcot foot usually causes little to no pain and may be slowly progressive over weeks to months before coming to a foot care provider’s attention. All health care providers can contribute to amputation prevention by referring patients with these signs and symptoms to a foot care specialist.

People with diabetes who have neuropathy are 1.7 times more likely to develop foot ulceration; in persons with both neuropathy and foot deformity, the risk is 12 times greater; and in those who also have a history of pathology (prior amputation or ulceration), the risk is 36 times greater (36, 37). Factors that increase risk for lower-extremity ulceration and amputation are male sex, the existence of diabetes for more than 10 years, tobacco use, a history of poor glycemic control, or the presence of cardiac, retinal, or renal complications (38–40).

Foot Complication Prevention

Up to 20% of people with diabetes who present for routine care will have a treatable foot care problem. Have the patient remove socks and shoes and inspect both feet for acute problems at each visit.
The lifetime incidence of foot ulcers among patients with diabetes is 15%. Most of these are preventable though interventions available in most primary care settings.
Patients with diabetes on dialysis are at extreme risk for foot complications. Foot care programs that provide outreach to this group are associated with improved foot outcomes.

Foot Evaluation in People with Diabetes

Podiatrists use the following considerations to assess the risk for complications when evaluating the feet of people with diabetes.

Comprehensive Foot Examination

A comprehensive foot examination for abnormalities, including evaluation of pulses, sensation, foot biomechanics (general foot structure and function), and nails helps determine the person’s category of risk for developing foot complications. Persons with diabetes who are at high risk have one or more of the following characteristics: (1) loss of protective sensation, (2) absent pedal pulses, (3) foot deformity, (4) history of foot ulcers, or (5) prior amputation. Low-risk individuals have none of these characteristics (41). Assessment of risk status identifies people who need more intensive care and evaluation. Further patient education, early intervention, and special footwear if indicated can prevent ulcers and ultimately LEAs.

Foot Risk Status

The American Diabetes Association and American Podiatric
Medical Association consider two categories of risk for developing
foot complications.

High Risk (one or more of the following):

Loss of protective sensation.
Absent pedal pulses.
Foot deformity.
History of foot ulcers.
Prior amputation.

Low Risk: None of these characteristics.

See text for interventions for patients with high- and low-risk feet.

Patient Education

The goal for low-risk patients is to keep them at low risk through control of the ABCs and tobacco cessation in those who use tobacco. In high-risk patients, the goal is to prevent ulcers though self-management education, podiatry care, and proper use of appropriate footwear. Minor trauma, such as stubbing a toe or stepping on a sharp object, is the most frequent precipitating event leading to ulcer. Emphasize to patients and their families the need to be diligent in clearing the walking spaces, especially around the bed and the path to the bathroom, and to use night-lights. High-risk patients also need to know when and whom to call with specific foot problems. Patients with a puncture wound, ulcer, redness, or new-onset foot pain should call and see their primary care provider or podiatrist that day. Patients with callus and/or thick or ingrown nails should call a podiatrist and be seen within a few days.

To obtain free print copies of these patient education materials, the Feet Can Last a Lifetime health care provider kit, and other materials on diabetes prevention and control visit www.ndep.nih.gov or call 1-800-438-5383.

High and Low-Risk Foot Patient Education

The goal for low-risk patients is to keep them low risk:

Control the ABCs.
Tobacco cessation.

The goal for high-risk patients is to prevent foot ulcers:

Self-management education:
Stress the role of minor trauma.
Clear walking spaces of potential hazards.
Prompt (same day) care for injuries.
Regular podiatry care.
Use appropriate footwear.

Foot Health and Diabetes

Prevalence of Foot Symptoms and Complications