CHAPTER 10 Lower extremity assessment
Chronic lower extremity ulcers are thought to affect from 0.5 to 1 million people in the United States at any given time (Bonham, 2003). Most of these wounds are chronic in nature, impact the individual’s quality of life, drain monetary and health care resources, and may even progress to possible limb loss if not managed appropriately. The key to successful management of any wound is an insightful assessment to determine the underlying cause so that treatment modalities address the pathologic factors. The etiologic factors of a lower extremity wound can be a myriad of diseases, infection, trauma, drugs, insect bites, pressure, or a combination thereof. Therefore, the wound specialist must be knowledgeable regarding clinical presentation and skilled in differential assessment. Critical assessment parameters are listed in Checklists 10-1 and 10-2 and described in this chapter.
CHECKLIST 10-1 Lower Extremity Physical Assessment
CHECKLIST 10-2 Diagnostic Tests for the Lower Extremities
The wound specialist must become familiar with, and proficient in, using proper descriptive dermatologic terms to describe primary or secondary lesions, the pattern of distribution, and the arrangement of lesions or other abnormalities. Careful description often leads the examiner to a specific disease state. Limb appearance should be compared with that of the contralateral limb to identify or rule out trophic changes. With the patient’s shoes and socks off, the wound specialist should visually assess both extremities for varicosities, color, pigmentation, turgor, texture, dryness, fissures, hair distribution, calluses, abnormal nails, fungus, bunions, corns, bony deformities, and skin integrity. The web between the toes should be assessed for hygiene issues (Bonham and Kelechi, 2008).
Trophic changes can occur when diminished blood flow can no longer support normal growth and development of the skin, hair, and nails. For example, thin and shiny epidermis, loss of hair growth, and thickened nails are often associated with, but are not diagnostic of, lower extremity arterial disease (LEAD). Conversely, edema, hyperpigmentation, scaly, eczematous skin, and varicosities (dilated, swollen, torturous) may be indicative of lower extremity venous disease (LEVD).
Trophic changes, however, are not definitive indicators of disease. Patterns of hair growth are affected by age and ethnicity as well as perfusion status, as hair growth may be diminished or absent in the elderly and certain ethnic groups. Nail growth is also affected by factors other than perfusion, including age and fungal infections.
The leg should be visually inspected or palpated for dilated veins, especially along the saphenous vein, beginning at the medial marginal vein on the dorsum of the foot and terminating at the femoral vein (about 3 cm below the inguinal ligament). Normally, healthy distended veins can only be visualized at the foot and ankle; the presence of dilated veins anywhere else on the leg may imply venous pathology and often is the first sign of venous insufficiency. Dilated veins, or varicose veins, are bluish, enlarged, and palpable. Often described as tortuous or rope-like, varicose veins are most often present on the back of the calf or on the inner aspect of the leg.
Small vessel changes can be detected with visual inspection. Small reddish or bluish “broken” vessels that cluster near the medial malleolus of the ankle are called spider or reticular veins; these can also be visualized anywhere on the leg. Ankle flare, a larger cluster of small vessels or sunburst, occurs around the ankle. Telangiectasias is the presence of fine, dilated capillaries.
The presence of any discoloration in the skin should be noted. For example, reddish-gray-brown hyperpigmentation in the gaiter region, more specifically hemosiderin staining (see Plate 34), is another skin color change that should be noted. Hemosiderin staining is hailed as the “classic” sign of LEVD, but it also can be found if significant trauma has occurred to the lower extremity. This type of discoloration develops after extravasated red blood cells break down and release the pigment hemosiderin.
Atrophie blanche, also seen with LEVD, is an atrophic, thin, smooth, white plaque with a hyperpigmented border, often “speckled” with tortuous vessels, occurring near the ankle or foot. Due to its scar-like appearance, atrophie blanche is easily and often mistaken for a previously healed ulcer (see Plate 35). Its presence is considered high risk for impending ulceration.
Tiny individual reddish-purple, nonblanching discolorations on the lower extremity may be observed. When the individual discolorations are larger than 0.5 cm, they are called purpura; when they are smaller than 0.5 cm they are called petechiae. Small blood vessels may leak under the skin and cause a blood or hemorrhagic patch that is a sign of some type of intravascular defect in individuals with normal or abnormal platelet counts. Purpura and petechiae (see Plates 36 and 37) are most often associated with LEAD (secondary to blood thinners) or vasculitis disorders such as systemic lupus erythematosus and polyarteritis nodosa (PAN). Purpura associated with vasculitis disorders is referred to as palpable purpura. Purpura that occurs in the elderly due to fragility of the vessels is known as senile purpura.
The presence of a condition known as lipodermatosclerosis should be noted as present or not present. Lipodermatosclerosis, a condition of the skin and soft tissues that develops in the presence of chronic swelling, is a progressive hardening or fibrosis of the soft tissues. Usually confined to the gaiter or “sock” area, lipodermatosclerosis may cause an inverted “champagne bottle” or “apple core” deformity of the lower extremity in sharp contrast to the unaffected leg.
Dermatitis (see Plate 38) manifested by scaling, crusting, weeping, excoriations (linear erosions due to scratching) from intense pruritus, erythema, or inflammation should be noted. Often these symptoms of dermatitis are misdiagnosed as cellulitis (see Table 12-3). Ulcers on the lower extremity should be noted in terms of their appearance, location, size, pain, and duration.
Edema is a localized or generalized abnormal accumulation of fluid in the tissues (WOCN Society, 2005). Numerous conditions can cause swelling of the lower extremity; examples include chronic venous disease, post phlebitis syndrome, iliac compression syndrome, lymphedema or lipedema, and systemic disease such as chronic heart failure, pulmonary hypertension and renal failure (Buczkowski et al, 2009). Edema causes swelling that may obscure the appearance of normal anatomy. To determine the presence of edema in the lower extremities, the appearance of one extremity should be compared with the other, noting the relative size and the prominence of veins, tendons, and bones. Edema is a significant finding in the examination of the lower extremity and should be investigated.
Evaluating edema is challenging due to lack of objective measurement methods. One method is to have the patient sit or stand and, using a flexible tape, obtain measurements of the lower extremity at the calf and the ankle. For valid comparisons, subsequent measurements must be obtained with the patient in the same position and exact location. Calf circumference is obtained by first marking the largest part of the inner calf with a marker and then taking a measurement from the floor up to this mark (in centimeters). This is the floor-to-calf length, and all future measurements should occur at this level. Second, the calf circumference (in centimeters) at the largest portion of the calf that was previously marked is measured. The ankle circumference is measured 5 cm above the ankle. Likewise, the floor-to-ankle length is determined by placing the tape measure at 0 cm on the floor and making a dot on the skin 5 cm above the medial malleolus and then determining the circumference of the ankle (in centimeters).
The extent of edema can also be assessed by pressing firmly but gently with the index finger for several seconds on the dorsum of each foot, behind each medial malleolus, and over the shins. Edema is “pitting” when there is a visible depression that does not rapidly refill and resume its original contour (Figure 10-1 and Box 10-1). Severity of edema can be categorized by either estimating the depth of the indentation (Figure 10-1) or the length of time for the indentation to resolve (Box 10-1). For clarity, the type of scale used should be recorded (e.g., 3+ pitting edema on a 4 point scale (Seidel et al, 2003).
(From Cannobio MM: Cardiovascular disorders, St. Louis, 1990, Mosby.)