The most common wounds of the lower extremity are venous, diabetic, neuropathic, ischemic, and pressure ulcers. 1 The quintessential assessment of any patient with a lower-extremity ulcer is a comprehensive history, physical assessment, and the use of special procedures or laboratory tests to arrive at a differential or specific diagnosis. This standard process is almost an art form because, although there are established protocols that should be followed in sequence, each individual patient presents with a unique set of circumstances that makes strict adherence to a formula almost impossible. This is especially true for patients with diabetes.
The secondary manifestations of diabetes, which affect the distal extremities, are well known. Under normal conditions, the peripheral neurovascular system provides sensation, proprioception, nutrition, oxygenation, and vascularization; it also allows for locomotion and protection from the environment. Diabetes (and its secondary complications) is particularly damaging to the afferent neurobiology of the peripheral neurovascular system, often resulting in a loss of protective sensation, foot and digital deformities, or a marked reduction in vascular perfusion of the lower extremity. As a result, the biomechanically altered, insensate, dysvascular foot is at high risk for ulceration and/or infection.
Diabetes is the sixth leading cause of death in the United States. 2 From 1990 to 1998, the prevalence of diabetes increased from 4.9% to 6.5%. 3 About 800,000 cases of diabetes are diagnosed in the United States each year. Approximately 17 million Americans—6.2% of the population—have diabetes, 5.9 million of them undiagnosed. Another 16 million have prediabetes (impaired glucose tolerance). 4 The objective of Healthy People 2000 was to reduce the incidence of diabetes to 2.5 cases per 1000 people and reduce prevalence to 25 cases per 1000 people. 5 Because these objectives were not met, they were renewed for Healthy People 2010. 6
Healthy People 2010 has 3 objectives specifically related to foot care for individuals with diabetes:
- an increase in the proportion of people with diabetes aged 18 years and older who have at least an annual foot examination (baseline, 55%; target, 75%)
- a decrease in foot ulcers due to diabetes (baseline and target figures are developmental)
- a decrease in lower-extremity amputations due to diabetes (baseline, 11 cases per 1000; target, 5 cases per 1000 per year). This objective is based on the estimate that at least 50% of amputations that occur each year in individuals with diabetes can be prevented through screening for high-risk patients and the provision of proper foot care.
The complications of diabetes are particularly devastating to the foot and often lead to amputation in the absence of early intervention. In 1997, 67% of hospital discharges for lower-extremity amputation were related to diabetes. 7 In addition, 85% of diabetes-related amputations are preceded by the appearance of a foot ulcer. 8
According to the National Institute of Diabetes and Digestive and Kidney Diseases, an average of 54,000 diabetic amputations were performed each year between 1989 and 1992. In addition, National Hospital Discharge Survey data for 1996 indicated that 86,000 people with diabetes underwent 1 or more lower-extremity amputations. 9 The total annual cost for these amputations was more than $1.1 billion dollars, excluding surgeons’ fees, rehabilitation costs, prostheses, time lost from work, and disability payments. 10 Furthermore, in a 1995 study, the average individual cost of a minor amputation averaged $43,000 and a major amputation cost $65,000. 11
The following factors associated with the diabetes disease process put the diabetic foot at risk for ulceration (and, ultimately, amputation):
- absent protective sensation
- vascular insufficiency
- foot deformities that cause areas of high focal pressure
- autonomic neuropathy that causes fissuring of the integument and osseous hyperemia
- limited joint mobility
- impaired vision
- poor glucose control that causes advanced glycosylation
- impaired wound healing
- history of foot ulceration
- history of previous lower-extremity amputation. 12
Although neuropathy is generally considered the most common complication of diabetes associated with ulceration, biomechanical instability and resulting deformities are usually present in patients with serious ulceration. Foot deformities are often unrecognized and inadequate protective footwear frequently causes tissue irritation and breakdown. Physical assessment of a patient with diabetes should be approached with an understanding that every diabetic foot is unique and requires treatment that is modified according to the presence of these risk factors.
Before examining a patient’s lower extremity, the practitioner should obtain a detailed history and perform a general physical examination. The complete patient history consists of the medical, family, and social histories.
The medical history should include all medical conditions that have been and are presently being treated. Patient care should be documented across the continuum of care, from the first practitioner to see the patient (usually the primary care physician) to the specialist. Verify and document care at each visit, including any changes in the patient’s treatment plan. The duration and course of the disease should be noted, including new complications that have developed, such as renal, ophthalmologic, or neurologic problems. Record the method that the patient uses to monitor his or her blood glucose level, along with the patient’s last blood glucose and hemoglobin A1c (HbA1c) levels. All medications, dosages, and patient allergies should also be documented. A detailed chronologic history of the presenting complaint should then be obtained.
A careful family history should be obtained, noting if any relatives have diabetes or have suffered from complications of the disease, such as eye or kidney disease, ulceration, or amputation.
Discuss social issues, such as tobacco, alcohol, or illegal drug use, with the patient. Professional counseling may be required to help patients minimize the use of harmful substances. Tobacco use has a devastating affect on the circulation and should be avoided. Alcohol use markedly elevates the blood glucose level and hastens the development of diabetic neuropathy.
Some attempt should be made to evaluate each individual’s living situation, including the amount of family support available to the patient. A simple test of a patient’s level of adherence is to assess whether they have taken the time to purchase a glucose meter and use it to test their blood glucose levels on a regular basis. Patients who know their daily blood glucose levels and have some idea of their HbA1c values are generally more adherent.
Finally, perform a detailed review of body systems to look for changes in the patient’s general health and to detect early signs of complications related to diabetes. A complete report that specifies the findings and suggested treatments should be sent to the patient’s primary care physician.
Physical examination of the lower extremity is based on assessment of the dermatologic, vascular, neurologic, and musculoskeletal systems (see Annual Comprehensive Diabetes Foot Exam Form on-line athttp://www.woundcarejournal.com).
The dermatologic examination should include visual inspection of the skin on the legs and feet, particularly the dorsal, plantar, medial, lateral, and posterior surfaces. Check behind the patient’s heel and between the toes and closely examine each of the toenails, which are frequently overlooked. Note if the character of skin changes from the more proximal leg to the more distal foot. Compare the skin on the feet to the skin on the arms and hands. Record any changes in color, pigmentation, texture, and turgor. The presence of calluses and their location, size, and color should be documented because they may indicate areas of mechanical stress or preulcer formation. Pigmentation in a specific area or over a diffuse area may indicate abnormalities, such as hemosiderin deposition related to venous or arterial insufficiency, chronic inflammatory conditions, or malignancy.
The texture of the skin is also an important indicator of the general health of the patient. Scaly skin may indicate a lack of hydration, anhydrosis secondary to diabetes, or a tinea infection. Skin turgor is the skin’s degree of resistance to deformation and is used to assess the degree of fluid loss. To measure turgor, tent the skin between 2 fingers, then release. Skin with normal turgor rapidly returns to its normal position. Skin with decreased turgor remains elevated. Accumulation of fluid in the tissue increases skin turgor and may be due to an edematous, infective, or traumatic process. 13
Other important observations include the presence of peeling skin and maceration or fissuring of the interdigital skin. Inspect the toenails for length, color, thickness, presence of subungal debris, odor, separation from the nail bed, and pain. The overall appearance of the nails is a good indicator of how much attention a patient pays to his or her overall foot health. Fissures on the heel or ball of the foot may lead to ulceration and should be treated with debridement and appropriate dressings.
Debride calluses to reduce pressure on underlying structures 14 and determine the cause of the lesion. Biomechanical control and off-loading of the callused area should be provided to reduce risk of skin breakdown and reoccurrence. Plantar calluses may be preulcerative and should be followed at regular intervals for debridement and off-loading as needed.
Three common skin disorders seen in patients with diabetes are diabetic dermopathy, necrobiosis lipoidica diabeticorum, and bullous diabeticorum. Diabetic dermopathy is characterized by round, reddish-brown papules found along the lower leg. Necrobiosis lipoidica diabeticorum presents with slowly enlarging, irregular, hyperpigmented plaques on the shins. Both are usually asymptomatic, generally resolve on their own, and may reappear spontaneously. Treatment for this disorder is difficult. Topical and intralesional steroids have been shown to reduce the duration and severity of the lesions. The disease goes through periods of exacerbation and remission with no known triggers to alert the practitioner to when the condition will flare up. Other treatments that have been shown to help include 1 daily aspirin, pentoxifylline, dipyridamole, and ultraviolet light.
Bullous diabeticorum presents as asymptomatic fluid-filled bullae found on the upper and lower extremities, which may be the result of vasculopathy. Treatment is not necessary unless the lesions break, then topical antibiotics or drying agents can be used. 15
Document any other dermatologic complaint and obtain a consultation with a podiatrist or dermatologist for overall care, if necessary.
Patients with diabetes should be considered at risk for peripheral vascular disease until proven otherwise. Initially, the practitioner should palpate for pulses bilaterally in the dorsalis pedis, posterior tibial, popliteal, and superficial femoral arteries. A commonly accepted grading system for pulse strength is: 0 = nonpalpable; 1 = weak, but present; 2 = normal; 3 = strong; and 4 = bounding.
Assess skin temperature using the back of the hand. Normal skin temperature ranges from warm at the tibia to cool at the distal toes. Many patients with diabetes, however, have no change in palpable temperature due to distal vasodilation related to autonomic neuropathy. Controlling their blood glucose levels, exercise, and a proper diet may help improve the circulatory status of patients with early mild disease.
Subpapillary venous plexus filling time should be assessed by pressing the distal pulp of a toe until it blanches, then counting the number of seconds it takes to return to a normal color. Normal reperfusion takes from 0 to 3 seconds. Immediate refill may be an indication of capillary atony associated with autonomic neuropathy; delayed refill is an indication of arterial ischemia. The absence of hair on the feet and digits may indicate inadequate circulation; however, the absence of hair is not a final indicator of vascular status. Examine the patient for edema in the ankle and/or foot, which may be pitting (soft fluid) or brawny (hard) due to venous insufficiency, lymphatic insufficiency, hypertension, or heart failure. Check for the presence of varicose veins, hemosiderosis (brown staining of the ankle area), and scarring from previous ulceration. Arterial insufficiency should be suspected when the patient experiences pain in the calf or foot on activity, which is relieved with rest (intermittent claudication).
Noninvasive tests for arterial insufficiency can be performed in the office setting, including calculation of the ankle-brachial index (ABI) and toe-brachial index (TBI). Calculate the ABI by taking the systolic blood pressure at the ankle and dividing it by the systolic pressure of the arm (both are measured by a Doppler). A normal ABI ranges from 0.9 to 1, moderate arterial disease from 0.75 to 0.89, severe arterial disease from 0.5 to 0.74, and limb-threatening total occlusion is below 0.5. However, ABI results can be misleading and should be used with caution in patients with diabetes, who may have elevated ankle pressures due to calcified vessel walls. 14 Because digital pressures may be more reliable for these patients, the TBI should be used. A hallux digital pressure is considered normal at 50 mm Hg; values of 30 mm Hg or lower are indicative of a significant decease in peripheral perfusion.
Other noninvasive tests may be used to help confirm ischemia. Pulse-volume recordings (PVRs) measure blood pressure along the lower extremity and quantify the change in size and shape of the waveform produced. 16 Segmental pressure tests with TBI may be combined with PVRs or used alone to determine ischemia. In addition, duplex B-scan ultrasonography of the lower limb allows for noninvasive quantitative assessment of blood flow and identification of areas with occlusion. The use of duplex ultrasonography has increased because its sensitivity and specificity rate is greater than 90%. 17
Although noninvasive vascular studies are useful general screening tools, they are not as reliable as invasive studies to determine the location and extent of occlusive disease. Coordinated care with an interventional radiologist and a vascular specialist is an integral component of caring for the patient with diabetes. 18 For example, magnetic resonance angiography (MRA) can be performed after injecting contrast media into the arterial tree. Specific areas of occlusion can then be easily identified, although the extent of the occlusion may be difficult to ascertain. Arteriograms are the standard of care for many facilities and newer techniques that utilize digital subtraction angiography provide enhanced contrast.
Deep tendon reflexes, light touch, 2-point discrimination, pain, and sharp/dull sensations may be diminished or absent in the diabetic foot. In fact, the absence of protective sensation is the single most important risk factor in the development of a foot ulcer. 19
To determine the degree of diabetic neuropathy, assess vibratory sensation with a tuning fork or a biothesiometer (Biomedical Instrument Corporation, Newbury, OH) or perform a quantitative assessment of light touch using a Semmes-Weinstein monofilament.
Vibratory sensation is usually tested with a 128 Hz cycle tuning fork, which is placed on the medial eminence of the first and fifth metatarsophalangeal joints, the base of the fifth metatarsal, the navicular, and the medial and lateral malleoli. The patient tells the practitioner when the vibration ceases and a subjective evaluation of the degree of sensory loss is made based on comparisons with the opposite, uninvolved limb or the patient’s hand. 20
A more accurate test of vibration is performed using a biothesiometer, which is operated by placing the testing head over a bony prominence and slowly increasing the vibratory wave. Patients without diminished sensation can feel vibrations at 25 volts or less. A vibratory perception threshold of 25 volts or more is indicative of peripheral neuropathy. 21
A more commonly utilized and less expensive method of testing for the absence of protective sensation is use of the Semmes-Weinstein 5.07 (10 gram) monofilament (see Assessing Protective Sensation with a Monofilament). The monofilament is applied at various locations on the foot, pressed until the filament bends halfway, and then released. The practitioner should apply the monofilament at several locations on the foot. Different studies have suggested sampling 5, 8, or 10 sites. It is the authors’ recommendation that the original 10 sites designated by the Carville Center be examined. These sites are the pulp of the first, third, and fifth digits; the plantar aspect of the first, third, and fifth metatarsophalangeal joints; the plantar medial arch (navicular) and the plantar lateral midfoot (cuboid); the plantar central heel; and the dorsal first web space. If the patient is unable to perceive the filament at 1 or more of the sites tested, the diagnosis of loss of protective sensation (LOPS) is made. 22
LOPS has been correlated with a risk of ulceration, especially in biomechanically unbalanced feet with secondary bony prominences, such as bunions or hammer toes. Patients with LOPS are unable to feel tight socks or shoes, foreign objects in the shoe, or even a puncture from a sharp object. Because these patients do not feel pain, they may continue to walk on small ulcers that enlarge and deepen, increasing the risk of deep space infection or osteomyelitis.
Deformity secondary to altered biomechanics of the foot is another significant risk factor for the diabetic foot, especially in the presence of neuropathy. LOPS alone without deformity may result in the development of an ulcer, but ulceration is more likely when these factors are combined.
A thorough mechanical examination of the patient should be performed, including an assessment of foot type, charting of deformities, and range of motion and muscle strength. No biomechanical assessment is complete without checking the patient’s shoes for appropriateness and wear and examining any orthotic devices (see Footwear Basics). Inadequate footwear frequently causes ulceration, and the patient should be referred to a pedorthist, if necessary.
Feet can be classified as flat or pronated, rectus or straight, and cavus or high-arched. Although ulcers occur in patients with neuropathy and rectus feet, they are more common in the other 2 foot types.
If the foot is flexible, orthotics designed to correct the pronated position may help unload the forefoot and reduce compensatory digital deformities. Fixed rigid deformities should be accommodated with total contact orthosis and depth footwear. Equinus secondary to glycosylation of connective tissue and mechanical adaptation can exacerbate hyperpronation of the foot and increase forefoot pressures in stance and gait. Pronation leads to increased pressure on the medial column of the foot that can result in the development of a pressure ulcer under the first metatarsal head. Digital contractures due to biomechanical imbalance and exacerbated by motor neuropathy lead to increased pressure on the dorsum of the toes and the plantar metatarsal heads. Hyperkeratoses, blisters, and ulcerations may occur at these sites of irritation.
Most pathomechanic abnormalities in the foot will lead to future irritation and increase the risk of ulceration. Biomechanical imbalance can be treated with custom-made orthotic inserts and specialized footwear. For more severe problems, such as open ulcerations or Charcot deformity, additional off-loading may be accomplished with bracing and custom footwear. Appropriate types of off-loading techniques and bracing may require consultation with a podiatrist, pedorthist, or an orthotist.
Patients with diabetes who have foot ulcerations can be referred to a podiatrist for debridement, wound care, specialized off-loading devices, or corrective surgery. Specific off-loading devices may include healing sandals, removable prefabricated walking casts, wedged or half-shoes, or total contact casting.
Patients with rigid deformities who are at significant risk for ulceration or who have a history of a previous ulcer may be candidates for elective foot surgery. Minor deformities can be addressed with relatively simple procedures. Patients with significant deformities or Charcot arthropathy may require more extensive reconstructive surgical procedures. Patients with well-controlled diabetes who are adherent with treatment generally experience few postoperative complications.
Proper physical assessment of the patient with diabetes at risk for foot ulceration, infection, or amputation may lead to prevention of lower-extremity complications and early intervention of identified pathology. Although practitioners routinely discover these problems during office visits, family members and other medical personnel can be trained to look for signs of diabetic foot pathology and can help an individual seek immediate attention for problems (see Foot Care Tips). A team approach, comprised of the patient’s primary care physician, endocrinologist, vascular surgeon, cardiologist, ophthalmologist, dermatologist, diabetic educator, and dietitian, greatly benefits the patient with diabetes and has been shown to help patients avoid preventable complications caused by the disease. 23
1. Goldstein DR, Mureebe L, Kerstein MD, Vogel KM. Differential diagnosis: assessment of the lower-extremity ulcer—is it arterial, venous, neuropathic? Wounds 1998; 10( 4):125–31.
2. Anderson, RN. Leading Causes for Deaths, 1999 National Vital Statistics Report. Hyattsville, MD: National Center for Health Statistics; 2001;49(11).
3. Mokdad AH, Ford ES, Bowman BA, Nelson DE, Engelgau MM, Vinicor F, Marks JS. Diabetes trends in the US: 1990–1998. Diabetes Care 2000; 23:1278–83.
4. National Institute of Diabetes and Digestive and Kidney Diseases. National Diabetes Statistics fact sheet: general information and national estimates on diabetes in the United States, 2000. Bethesda, MD: US Department of Health and Human Services, National Institutes of Health, 2002.
5. United States Department of Health and Human Services. Healthy People 2000: Final Review. Washington, DC: Government Printing Office; 2000.
6. United States Department of Health and Human Services. Healthy People 2010: Understanding and Improving Health. Washington, DC: Government Printing Office, 2000.
7. Centers for Disease Control and Prevention. Hospital discharge rates for nontraumatic lower extremity amputation by diabetes status—United States, 1997. MMWR 2001; 50( 43):954–8.
8. Dinh T, Pham H, Veves A. Emerging treatments in diabetic wound care. Wounds 2002; 14( 1):2–10.
9. National Hospital Discharge Survey, 1996. Centers for Disease Control and Prevention, National Center for Health Statistics, Division of Health Care Statistics. Data Computed by the Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion.
10. Levin, ME. Preventing amputation in the patient with diabetes. Diabetes Care 1995; 18:1383–94.
11. Apelqvist J, Ragnarson-Tennvall G, Larsson J, Persson U. Long-term costs for foot ulcers in diabetic patients in a multidisciplinary setting. Foot Ankle Int 1995; 16:388–94.
12. Boyko EJ, Ahroni JH, Stensel V, Forsberg RC, Davignon DR, Smith DG. A prospective study of risk factors for diabetic foot ulcer. The Seattle Diabetic Foot Study. Diabetes Care 1999, 22:1036–42.
13. Jelinek JE. Dermatology. In: Marvin EL, O’Neal LW, Bowker JH. The Diabetic Foot. St. Louis, MO: Mosby-Yearbook; 1993.
14. Hoffman, AF. Evaluation of arterial blood flow in the lower extremity. Clin Podiatr Med Surg 1992; 9( 1):19–56.
15. McNeely MJ, Boyko E, Ahroni JH, et al. The independent contributions of diabetic neuropathy and vasculopathy in foot ulceration: how great are the risks? Diabetes Care 1995; 18:216–9.
16. Whelan JF, Barry JH, Moir, JD. Color flow Doppler ultrasonography: comparison with peripheral arteriography for the investigation of peripheral vascular disease. J Clin Ultrasound 1992; 20:369–74.
17. Eze AR, Comerota AJ, Cisek P, Holland BS, Kerr RP, Veeramasuneni R, Comerota Jr. AJ, Intermittent calf and foot compression increases lower extremity blood flow. Am J Surg 1996; 172:130–5.
18. Thivolet C, el Farkh J, Petiot A, Simonet C, Tourniaire J. Measuring vibration sensations with graduated tuning fork. Simple and reliable means to detect diabetic patients at risk of neuropathic foot ulceration. Diabetes Care 1990; 13:1077–80.
19. Caputo GM, Cavanagh PR, Ulbrecht JS, Gibbons GW, Korchmer AW. Assessment and management of foot disease in patients with diabetes. N Engl J Med 1994; 13:854–60.
20. Bloom S, Till S, Sonksen P, Smith S. Use of a biothesiometer to measure individual vibration thresholds and their variation in 519 non-diabetic subjects. Br Med J 1984; 288:1793–5.
21. Fernando DJ, Masson EA, Veves A, Boulton AJM. Limited joint mobility: relationships to neuropathic ulceration. Diabetes Med 1992; 5:333–7.
22. Birke JA, Sims DS. Plantar sensory threshold in the ulcerative foot. Lepr Rev 1986; 57:261–7.
23. Holstein PE, Sorenson S. Limb salvage experience in a multidisciplinary diabetic foot unit. Diabetes Care 1999: 22 (suppl 2):97–103.
FOOT CARE TIPS: Pointers to share with patients and their caregivers
- Take care of your diabetes.
Check your feet every day.
- Work with your health care team to keep your blood sugar within a good range.
Wash your feet every day.
- Look at your bare feet every day for cuts, blisters, red spots, and swelling.
- Use a mirror to check the bottoms of your feet or ask a family member for help if you have trouble seeing.
Keep the skin soft and smooth.
- Wash your feet in warm, not hot, water every day.
- Dry your feet well. Be sure to dry between the toes.
Smooth corns and calluses gently.
- Rub a thin coat of skin lotion over the tops and bottoms of your feet, but not between your toes.
If you can see and reach your toenails, trim them each week or when needed.
- If your feet are at low risk for problems, use a pumice stone to smooth corns and calluses. Don’t use over-the-counter products or sharp objects on corns or calluses.
Wear shoes and socks at all times.
- Trim your toenails straight across and file the edges with an emery board or nail file.
Protect you feet from hot and cold.
- Never walk barefoot.
- Wear comfortable shoes that fit well and protect your feet.
- Feel inside your shoes each time you put them on to make sure the lining is smooth and that there are no objects inside.
Keep the blood flowing to your feet.
- Wear shoes at the beach or on hot pavement.
- Wear clean socks at night if your feet get cold.
- Don’t test bath water with your feet.
- Don’t use hot water bottles or heating pads.
Be more active.
- Put your feet up when sitting.
- Wiggle your toes and move your ankles up and down for 5 minutes, 2 or 3 times a day.
- Don’t cross your legs for long periods of time.
- Don’t smoke.
Check with your health care provider.
- Plan your physical activity program with your doctor.
Get started now.
- Have your health care provider check your bare feet and find out whether you are likely to have serious foot problems. Remember that you may not feel the pain of an injury.
- Call your health care provider right away if you find a cut, sore, blister, or bruise on your foot that does not begin to heal after one day.
- Follow your health care provider’s advice about foot care.
- Begin taking good care of your feet today.
- Set a time every day to check your feet.
Source: National Diabetes Education Program. Feet Can Last a Lifetime. A Health Care Provider’s Guide to Preventing Diabetes Foot Problems. Bethesda, MD: National Institute of Diabetes and Digestive and Kidney Diseases and National Institutes of Health, November 2000. On-line at http://www.ndep.nih.gov/materials/pubs/feet/feet.htm.
ASSESSING PROTECTIVE SENSATION WITH A MONFILAMENT
A Semmes-Weinstein monofilament is commonly used to assess protective sensation in the feet of patients with diabetes. The 5.07 (10 gram) monofilament wire is applied to each foot at 10 sites—the pulp of the first, third, and fifth digits; the plantar aspect of the first, third, and fifth metatarsophalangeal joints; the plantar medial arch (navicular) and the plantar lateral midfoot (cuboid); the plantar central heel; and the dorsal first web space. Loss of protective sensation generally is indicated by a patient’s inability to feel the monofilament at 1 or more of 10 sites. The following pointers should assist in ensuring that the procedure is done correctly:
- Place the patient in a supine or sitting position. His or her legs should be supported and shoes and socks should be removed. Touch the monofilament to the patient’s arm or hand to demonstrate what it feels like. During the test, the patient should respond “yes” each time the pressure of the monofilament is felt on the foot.
- Make sure the patient’s feet are in a neutral position, with toes pointing straight up. The patient should then close his or her eyes so that the test can begin. Hold the monofilament perpendicular to the foot, press it against the first site, increasing the pressure until the monofilament wire bends into a C-shape. Make sure it does not slide over the skin. The device should be held in place for about 1 second. After the patient responds, record the response on a foot screening form. A “+” should be used for a positive response and a “-” for a negative response. Then move to the next site.
- Remember to test sites in random order and to vary the time between applications. That way, the patient will not be able to guess the correct response. If the patient has an ulcer, scar, callus, or necrotic tissue at the test site, apply the monofilament along the perimeter of the abnormality, not directly on it.
- Refer the patient for an intensive education and follow-up program to learn how to inspect and protect the feet if the test indicates he or she is experiencing loss of protective sensation. The patient can be taught self-assessment with the monofilament, but it does not replace a professional evaluation.
From: Sloan HL, Abel RJ. Getting in touch with impaired foot sensitivity. Nursing98 1998; 28 ( 11 ): 50–1.
Whether a patient with diabetes is using the appropriate footwear will depend on the degree of risk for ulceration and/or the presence of active or recently healed ulceration. Patients who lack protective sensation and who have a history of foot deformity, ulceration, or amputation of any part of the foot should be referred to a podiatrist for an evaluation for special shoes or orthotics.
Patients who still have protective sensation and no history of foot deformity or ulceration generally do not need custom shoes. There are criteria for appropriate footwear, however, that will help to ensure that the patient remains ulcer-free. For a proper shoe fit, the person should be standing when measured for shoes. The ball of the foot (metatarsal head) should correspond to the widest part of the shoe. The shoe must not cause discomfort or skin irritation; shoe-related repetitive pressure has been associated with ulceration.
The following are characteristics of ideal footwear for any person with diabetes:
- Laced shoes offer maximum adjustability.
- Calfskin offers flexibility and breathability.
- Secure-fitting heels avoid friction.
- Wedged soles offer greater support than a separate heel and toe.
- Cushioned crepe soles provide traction and comfort.
- Heels should not be higher than 1 inch.
- Pointed-toe shoes should be avoided; a wide toe box is best.
- Maintain ½ inch between the longest toe and the end of the shoe.
- The shoe should bend easily at the ball of the foot.
- The shoe should have adequate arch support.
It is best to consult with a specialist, such as a pedorthist or a podiatrist, before making a recommendation.
From: Umeh L, Wallhagen M, Nicoloff N. Identifying diabetic patients at high risk for amputation. Nurse Practitioner 1999; 24 ( 8 ): 56, 60, 63–6, 69–70.