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Chapter VI

CLINICAL ASSESSMENT

HISTORICAL REVIEW, EVALUATING SYMPTOMS,

PHYSICAL EXAMINATION, FOOTWEAR EXAMINATION

Foot examination in diabetic foot patients is very vital. All the diabetic patients must undergo routine foot examination at every follow up visit.

Clinical Assessment

Time efficient assessment procedures and documentation to detect foot at risk is a necessity. Tracking changes on follow up and taking appropriate steps for prevention of progression of foot for further risk of ulceration is also necessary. In the multifarious monitoring required for good diabetes care, monitoring for feet becomes an additional element that needs to be woven in the fabric of our monitoring and recording systems. For that we must make allowance of optimal time, decide on the frequency of tests and the modalities we will be using to do the testing and provide for appropriate interventional strategies.

For this purpose tools should be simple to use and yet comprehensive enough. We should also be able to develop manpower for our help to use them.

The assessment of diabetic foot:

Broadly this will fall into -

Historical review, clinical examination and laboratory assessment:

The historical review will consist of neuropathic symptoms, claudication or rest pain and previous history of ulceration as the main areas of enquiry. Depending upon the time availability detailed Neuropathic Symptom score analysis can be undertaken. Extensive symptoms and deficit scores are available but a baseline symptomatic enquiry at least should be undertaken. The findings on examination are important to guide for planning further actions. Quantitative measurements of neuropathy and vasculopathy lend the examination a far revealing profile of the foot at risk and planning for intervention.

Historical review:

This consists of a series of questions that should be asked systematically and quickly to get an idea of the more pertinent examinations we should focus on more than others. It should give a clue to decide on the areas that may need more detailed and frequent testing, with sophisticated methods. A detailed review for our diabetic patients should be done on the first occasion. If more time is required for special testing on these patients, they should be called by separate appointment. If it is not feasible as the patients often travel over long distance, we should have a mechanism by which such patients are given extra time in the day and assessed.

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Following is a brief review of important historical aspects and the interpretation of some of them.

Is there any abnormal sensation in your feet?

The abnormal sensations are classified in three groups:

Dysesthesia, parasthesias and muscular pain.

Dysesthesia is described variously as burning sensation, sunburn like sensation, skin tingles, it is useful to ask the time of the day. Many a times, the sensations are worse at night. Excessively painful sensation on such slight touch that normally should not hurt - e.g. bed sheets or stockings, is called as Allodynia.

Parasthesias are variously described as pins and needles, electric like, numbness but aching, like feet in ice water, knife like, shooting pain, lancinating pain.

Muscular pains: They are characteristically described as dull ache, night cramps, band like sensation, deep aches, spasms or toothache like (throbbing).

Is there a decrease in the ability to feel the surface features, texture, temperature, shape, irregularity or unevenness when he walks?

Weakness in hands: This could be ascertained by asking if the patient can zipper, button his clothes or can handle coins, manipulate a key or weakness felt while extending the fingers. The inability or impairment will indicate muscular weakness.

Weakness in legs: Whether the patient flaps his legs or if he can carry his weight on the heels and walk or if he can walk on his toes.

The symptoms can be most profitably recorded on the 3 elements suggested by Dyke and Thomas, viz., 1) Whether the symptom is present or absent, 2) what is the severity of the symptoms and 3) what is the change in those symptoms as compared to the last visit (during subsequent examinations). This neuropathic symptom score is a reliable standard and well-tested system that can be used in practice and has stood the tests of Clinical trials and the epidemiological studies.

Gait:

The foot examination should start by watching how a patient walks.

Autonomic Neuropathy:

Do they feel faint on getting up?

Is there any loss of bladder control?

Do they feel excessively bloated on food?

Is there constipation of recent origin /

increasing severity?

Is there sexual dysfunction?

The examination -

F Gait F Skin F Deformities

F Nails F Joints

F Hair / web spaces / callus and corns

F Palpation of the feet

F Assessment of sensory neuropathy

F Assessment of motor neuropathy

F Assessment of vascular status

F Foot wear and socks

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A patient with neuropathy may walk with high stamping gait when proprioception is lost.

A patient with ulcer who does not walk with limp is likely to have severe neuropathy. Patients with distal symmetrical polyneuroapthy walk with wide gait and are prone to observe the floor while walking.

Many patients have foot drop. They walk with the foot scraping the floor, or with a high stamping gait.

If the patient walks with slippers that slide out of the foot it indicates significant sensory neuropathy.

Changes in the skin:

The skin should be examined for

Dryness: Dry skin is more likely to develop ulcers. It is also suggestive of autonomic neuropathy making it prone to Charcot's arthropathy. (Fig. 19,20)

Loss of hair over the dorsum: This will signify vasculopathy. (Fig 23) This will signify vasculopathy. (Fig 23)

Cracks: The heel skin cracks develop more commonly in a patient who walks bear foot. The condition of the cracks should be noted. The depth, edges and the presence of bleeding from the edges are important points that should be looked for. (Fig 34)

Calluses and corns: The formation of callus / corns denotes pressure points, the unequal load on the foot and or footwear that may be pressing at those points. Blisters at pressure points should be noted as they indicate an impending ulcer.

The condition of the skin at the heads of metatarsal should be examined for early signs of ulcer or redness that may indicate inflammation and will indicate need for resting the feet immediately.

The presence of web space fungus infection is an alarm sign, which requires vigorous treatment. The toes should be separated and the condition of the skin observed.

Ulceration.

Erythema.

Turgid veins will indicate the possibility of autonomic neuropathy with AV shunting.

Signs of pruritus could indicate dryness.

Fungal infection could be potentially dangerous. (Fig24)

Examination of deformities:

Broadly one may look for:

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Clawed toes: the toes are bent ventrally. They are susceptible to ulceration as the tips are subjected to friction and abnormal pressures. (Fig 25)

Hammer toes or cock up toes are bent upwards and will rub against the upper of the shoes and will be prone to ulceration.

Pes cavus - highly arched foot with plantar flexion. (Fig 26)

Flattened arches, especially medial, will indicate collapse of the arches and severely damaged foot architecture, also indicative of Charcot's arthropathy.

Lateral dislocations or migration of toes makes the toes susceptible to friction and abnormal pressures and can injure the adjacent toes with the deviated nails. (Fig 28)

Plantar dislocation of toes results in areas of excessive pressure.

Plantar dislocation of the tarsus and Sub-talar dislocation causing rocker bottom deformity is indicative of gross destabilisation of the foot. (Fig 30)

Crowding of toes can injure the adjacent toes with the nails. (Fig 13)

Hallux rigidus: an unbending great toe becomes exposed to repeated trauma and ulceration. (Fig 16)

Foot shape should be documented regularly on the basis of the observations made above. The neoglycation also causes contraction of plantar fascia and extensor tendons. This increases the height of the foot. It is called as Windlass deformity. All these deformities occur at different stages of neuropathy. Early detection of deformities can prevent further collapse of foot by taking appropriate measures to stabilize the foot. It should be examined in detail as these will finally lead to ulceration.

Nails:

The condition of nails is a fair indicator of the severity of neuropathy and vasculopathy. The nails of a neuropathic foot are hard but brittle. (Fig 31)

The nails of a vasculopathic foot are brittle and ivory in appearance. (Fig 32)

The pattern of nail trimming by the patient is indicative of the level of foot care observed by the patient.

If they are over grown in that case they need to be cut, if required by a double action bone nibbler.

In growing toe nails: They should be carefully examined and documented, as these nails are a source of infection and will be required to be excised.

Injuring adjacent toes: This finding calls for a toe separator and wider toe box in shoes.

Partially avulsed, brittle, unhealthy nails should be trimmed.

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Keratosis under the nails- injuring the subungual tissues.

The condition of the subungual tissue should be noted. The excessive growth of subungual tissue is indicative of level of neuropathy and the level foot care by the patient.

The Joints:

The flexibility of the joints is an important etiological factor in the causation of an ulcer. The most important joint is 1st MTP joint. The process of glycation causes changes in the tissues, which cause loss of elasticity. This reduces mobility of the joints. Loss of flexibility of 1st MTP joint if detected early should be treated by advising the patient to move those joints early so that it does not progress and thereby can reduce the possibility of the ulcer formation. Therefore at every follow up examination degree of flexibility of the 1st MTP joint should be tested. Similarly the loss of mobility of the other joints like that of hand can be tested by asking the patient to put the palms together in NAMASTE position. This prayer sign is positive if there is a gap left in the two little fingers as they appose. (Fig 33) Asking the patient to pick up the socks from the floor with toes can also be a simple test to judge the degree of flexibility of the joint.

Hair:

Dry discolored or friable hair indicate vasculopathy.

Hair follicles with furuncles.

Web spaces:

Fungal infection.

Maceration is an alarm sign as it indicates a sub optimal status of the integrity of the skin.

Callus / Corn examination:

The callus is flat and diffuse while corn is circumscribed and is painful on vertical pressure. Callus is a semi emergency situation in diabetic foot management. No diabetic patient should be allowed to continue walking with callus. The site of the callus as well the nature should be documented. A hard callus at pressure point is indicative of wrong footwear or unprotected walking by the patient.

A callus with bleeding denotes breakdown of callus and ulcer formation. The ulcer is usually hidden under the callus and becomes apparent only when the callus is excised. Both callus as well as corn cannot develop unless there is unequal / undue pressure on the skin either due to the changed shape of the foot or wrong foot wears. If the callus is ulcerated then the depth of the callus as well as the undermined edges should be probed.

The most common site of the callus is on the MTP joints usually on the 1st MTP joint. Inter-digital callus is usually due to crowding of toes, friction and injury due to adjoining toe nail.

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The callus of the neuropathic and vasculopathic foot is different qualitatively. The callus in case of vasculopathic foot is glazed in nature and is thick. The callus in neuropathy is proliferative, hard, has a peculiar smell, which attracts the insects. In fact the proliferation is many times so excessive that it looks like a malignant growth.

The other variety of callus is soft callus, which is due to a neuropathic callus getting infected or macerated. Both these conditions require prompt recognition and treatment.

Palpation of feet:

See whether the feet are lying symmetrically. If not they will indicate unequal muscle power.

Hold the feet firmly between the two hands to see if they are unusually cold or one is colder than the other. This indicates vascular compromise if cold and AV shunting if it is warm.

Pain: Localized areas to be palpated for pain. It could indicate deep-seated abscess.

Feel for dorsalis pedis, anterior tibial, popliteal and femoral on both sides by the standard clinical methods to observe if the pulsations are equal.

Assessment of sensory neuropathy:

Proper and correct quantification and evaluation of neuropathy is essential for staging the diabetic foot problem as well as to use predictive parameters. Diabetic neuropathy is distal symmetrical polyneuropathy.

Test the touch sensation by cotton wool: Sense of the touch is very important to diagnose the foot at risk. Loss of sense of touch is a danger sign in diabetes.

Proprioception in toes:

Usually position sense is altered at a late stage in distal symmetrical neuropathy. Hence in diabetes if position sense is altered at a relatively early stage, then a diagnosis other than that of neuropathy, need to be entertained. To test position sense the first toe should be wriggled for few times and after asking the patient to close the eyes the patient should be asked to identify the position.

Two point discrimination:

An unwound paperclip or the divider can be used. However the correct method, if available, is the use two-point discrimination wheel. The distance of 2 mm or less than 2 mm is normal on the pulp of the toes. Distance of more than 2 mm signifies nerve fiber damage. The points to be tested are fingertip and toe tip, preferably first toe.

Pain sensation:

Using pinwheel can test pinprick. The patient must be explained the procedure. He must experience the sharp and dull feel of the pinwheel on the face. The pinprick is

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tested in upper extremity from tip of the middle finger to the elbow joint on the volar surface and on the leg from tip of the toe to the knee on dorsal surface and up to heel on the plantar surface. The testing should be done from distal to proximal and documented by dividing the area in multiple small units. The score should be documented as dull / sharp / absent / normal.

Vibration by a simple tuning fork:

Vibration sense can be quantified by two methods. The commonly used method is to test with 128Hz tuning fork and test on the bony points like malleoli and tip of the 1st toe. The other method is by Biothesiometer described in the section of laboratory assessment.

If there is doubt if the patient has difficulty in sensing the vibration, this needs to be investigated further as it gives important information for better care. These qualitative findings should be quantified.

Suffice it to say that all testing need not be carried out at one go as it is time consuming and can exhaust the patient. It can be carried out subsequently in a review appointment fixed at a relatively shorter interval. It is essential that the patient be told that due to constraint of time, some of the more detailed assessment that should be carried out will be done in the next visit. It may not be out is place to even to tell the patient to remind you of it the next time he / she comes.

Assessment of motor function:

An important lesion the neuropathy produces is the weakness of the small muscles of the foot. This motor neuropathic manifestation causes intrinsic destabilization of foot, its anatomical position and leads to deformity, foot drop due to the weakness of dorsal flexors or the various proximal motor neuropathies that result in group wasting of muscles.

From the point of the view of assessment of the motor function following testing would be considered important.

1. The muscle girth measured by flexible tape at the thigh and leg level by selecting a level from a bony point on both the sides.

2. Testing for foot drop by asking the patient to lift his foot dorsally first without

resistance but only anti gravity. If he/she can do that the patient should be asked to

dorsiflex against minimal and gradually increase resistance. Similarly the strength of

plantar flexion could be tested against resistance. It should be then graded and

entered.

3. The flexion and extension at knees and hips should be carried out after that. The tone

of the muscles should be tested. Gastrocnemius and soleus are flexors of the ankle

joint and their tightness will reduce the ankle flexion, which is important for walking.

4. Motor stretch reflexes at the ankle and knee. Deep tendon reflexes of upper and lower

extremity are part of normal neurological evaluation. The strength of the muscles

should be tested for both upper and lower extremities and graded as per the 0 to 5.

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5. Plantar reflexes to detect pyramidal involvement that may lead to permanent

hypertonic plantar flexion and could become liable to pressure points.

6. It is always advisable to check for at least the flexion and extension particularly at hips because the proximal femoral neuropathy or diabetic amyotrphy is self-limiting. It is necessary to reassure patients on that.

A Note on Painful Neuro-Radiculopathy in Persons with Diabetes:

It is a useful practice to know the direction in which the pain progresses. If the pain is described as shooting down the thigh or leg from the hip or from the back and is confined to one leg or part of one leg it is likely to be a radicular pain of which the cause is more likely to be located in the spinal canal. The compressive radicular pains are likely to be present along with painful neuropathy. It is important to distinguish this because it changes the line of further investigation. Moreover, it is for us clinicians that we distinguish these two and focus our attention on referrals properly.

This is important because many a times a radicular pain may be relieved but the neuropathic pain or numbness may persist, even after the surgical intervention. This is an embarrassing situation to the surgeon as well as the physician because they have,

1. Not differentiated between the two.

2. Not assessed the two separately.

3. Not given an idea to the patient as to what is likely to be relieved by surgery and what

is likely to persist and

4. Have not explained that medication will be required even after surgery.

All these aspects are important to distinguish and told to patients if intervention is planned and give a clear idea of what cold be relieved and which symptoms are likely to persist.

The assessment of vasculopathy:

The general appearance of the vasculopathic foot is dry, with a dusky skin, atrophy of the nails, presence of skip lesions and vascular ulcers.

The quantification of vasculopathy is both clinical and by investigations. The clinical examination involves palpating pulses at ankle, knee and hip joints. The thickness of vessels, volume of pulse and presence of dilated veins and status of venous and capillary return should be tested.

Capillary return is tested in the following manner. Press on the ball of a toe, to blanch it completely. Release the pressure. Watch for the return of the blood resulting in the colour as it was before pressure and note the time. If it is less than 15 seconds, the circulation is adequate.

Dilated veins are present in autonomic neuropathy due to AV shunting.

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If the arteries are palpable at ankle and knee level ankle / brachial index should be measured. The method of doing this is to tie a BP cuff between knee and ankle joint and measure the pressure by palpating either Dorsalis Pedis or Posterior Tibial artery. Then take the brachial artery pressure. Divide the ankle arterial pressure by the brachial artery pressure. This is the value of Ankle Brachial Index. If the index is less than 0.7 then the further evaluation of vasculopathy is required. Index above 0.7 is usually compatible with conservative wound healing. However one of the major fallacies of this index is that in the presence of severe arteriosclerosis, usually the index is high and that is a false positive result, which is not useful as a predictive parameter.

Similarly by palpating popliteal artery, index at knee level can be measured.

If the vessels are not clinically palpable then hand held Doppler should be used to measure the index. In such cases colour flow Doppler examination would reveal the site and nature of the block. Presence of high index with other clinical signs of ischemia like claudication, low volume pulse and skin changes, denote arterial block at a higher level. This can be further confirmed by peripheral angiography to assess the feasibility of revascularisation. At every visit of a diabetic patient the vascular assessment should be done and documented. Also if the patient has claudication then the nature of the claudication as well as the claudication distance should be documented. This helps in judging the progression of the vasculopathy or the improvement in the collateral circulation.

Footwear and socks:

When patient walks the type of the footwear he is using and how it is placed in the foot should be noted. Most of the times the heel slides out and this can cause the heel ulcers / fissures or cracks. Patients should be asked to take out the footwear and following points related to the footwear should be noted:

Whether the size of the foot wear is correct? The correct size of the footwear is measured as follows. The length should be 2-3 mm longer than the longest toe which is usually second toe. Measuring the distance between 1st and 5th metatarsal heads and keeping 2-3mm extra space on both the sides decides the adequate width. The height of the shoes should be 2-3 mm more than the highest point of the mid foot.

The method of Steno Diabetes Centre:

To judge the adequacy of the footwear to the foot size and the level of compatibility between the two, Steno Diabetes Center, Copenhagen Denmark, has popularized a simple method. A person with diabetes is asked to stand on a firm and even ground on an A 4 size paper. Another person draws an outline of both his feet by using a pencil and tracing it along the margins of the foot without angling it. The outline then is cut on the lines carefully to get the foot shape as exactly as possible. This foot shape is then inserted in the foot ware the patient uses, fully and as evenly as possible. The foot shape is taken out and examined for wrinkles on the foot shape inserted. If wrinkling is found then obviously that is the place where the foot is coming under pressure from the foot ware. It is a highly effective method of testing the foot ware and convincing the patient that his foot ware is not what it should be and that it needs revision.

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Insoles:

The insoles should be taken out of the shoes and should be inspected for wear and tear and especially for the impression of the 1st MTP joint. The outsole should be observed for extent of flexibility at MTP joints or the extent of rigidity if any. The wearing out of the heels should be noted as this signifies method of walking. For example, if the patient's heel is worn out on lateral side then this will signify that patient walking with overloading the lateral arch of the foot. This may require basic changes in the footwear.

The type of the laces and /or Velcro straps used in the footwear should be inspected, before patient takes out the shoes. The method of tying the shoes laces and whether the footwear straps are tight or inadequate should be noted.

Whether the patient wears the socks with the footwear should be determined first. Socks reduce the shear forces. The condition of the socks should be inspected and documented. This has important bearing on the shear force damage to the fore foot. The socks in diabetic patient will show wear and tear at pressure points. Also the socks, if white (as they should be) will show stains at the point where the skin breaks down. The elastic of the socks should be tested for tightness as this can impede the venous and lymphatic drainage causing oedema of the feet.

THREE IMPORTANT FACTORS REQUIRED FOR DIABETIC

FOOT WOUND HEALING

1. OFF LOADING OF AFFECTED FOOT

2. TOTAL DEBRIDEMENT

3. ADEQUATE VASCULARITY