The Diabetic Foot

Question 1

What are the two complications of diabetes that predispose to foot disease?

Answer 1

Diabetic Neuropathy - all 3 of sensory, motor and autonomic neuropathy influence development of foot disease

Peripheral vascular disease - macrovascular complication of diabetes

Question 2

What is the main cause of diabetic foot disease?

Answer 2

Distal sensory neuropathy

Question 3

What are the conditions that are associated with development of diabetic foot disease?

Answer 3

1) Sensory neuropathy (microvascular damage to the blood supply to the nerves)
2) Motor neuropathy - develop clawing of the toes due to paralysis of the long extensors/flexors of their feet/toes, indicates that sensation of difference in weight distribution through the foot has been lost as well
3) Limited joint mobility - sugar binding to the collagen in the tendons makes them less flexible reducing joint mobility, patients will be unable to place their hands flat together
4) Autonomic neuropathy - no release of oils into skin so skin breaks down
5) Peripheral vascular disease
6) Trauma - repeated unnoticed minor/discrete events
7) Reduced resistance to infection
8) Other diabetic complications e.g. retinopathy

Question 4

What can be used to look at the arterial beds and assess macrovascular damage of these beds?

Answer 4

Multi-station contrast-enhanced magnetic resonance angiograph
- shows where large vessels and arterial beds have lost circulation

Question 5

How does the neuropathic foot present with foot ulceration?

Answer 5

Numb (sensory neuropathy)
Dry (autonomic neuropathy)
Loss of reflexes
Warm
Palpable foot pulses
- Ulcers occur at points of high pressure loading that haven't been sensed

Question 6

How does the ischaemic foot present with foot ulceration?

Answer 6

Cold
Pulseless
- Ulcers at the foot margins

Question 7

Given the features of the neuropathic and ischaemic foot, how does the neuro-ischaemic foot present with foot ulceration?

Answer 7

Numb
Dry
Cold
Pulseless
- Ulcers at points of high pressure loading AND at foot margins

Question 8

Why are the features of a foot with ulceration/s important?

Answer 8

Weighs in on which treatment option is the best - i.e. does the patient need an angioplasty to improve blood flow (ischaemic foot) or just to take weight off the foot and let it heal(neuropathic foot)?

Question 9

How is the foot of a diabetic patient assessed?

Answer 9

Appearance - how does it look? are there deformities? calluses?

Feel - how does it feel? hot/cold? dry?

Foot pulses - check for dorsalis pedis/posterior tibial pulse to check blood flow to the foot

Neuropathy - vibration sensation, temperature, ankle jerk reflex, fine touch sensation

Question 10

How is diabetic foot disease managed from a diabetes perspective?

Answer 10

Control blood sugar - reduce hyperglycaemia
Control blood pressure - reduce hypertension
Control dyslipidaemia - try to stop or slow the progression of atheroma
Stop smoking if they do
Education - educate the patient

Question 11

What are the steps in preventative management of diabetic foot disease?

Answer 11

1) Control diabetes
2) Inspect feet daily
3) Buy bigger and more comfortable shoes
4) Buy shoes with laces and square toe box
5) Inspect inside of shoes for foreign objects
6) Attend chiropodist
7) Cut nails straight across
8) Care with heat and testing heat
9) Never walk barefoot (burning on hot sand, small stones etc)

Question 12

What is the approach to treatment of diabetic foot disease in terms of personnel and who is involved?

Answer 12

Multidisciplinary team approach
- diabetologist
- diabetes nurse
- chiropodist
- orthotist
- vascular surgeon
- orthopaedic surgeon
Potentially a limb fitting centre in cases of disabling amputation

Question 13

What is the role of the diabetologist and diabetes nurse in management of diabetic foot disease?

Answer 13

Both need to help educate the patient
- diabetes nurse must take them through all the aspects of care the patient must go through and to help control their blood glucose

Question 14

What is a vascular surgeon needed for in management of diabetic foot disease?

Answer 14

To try and improve blood flow to the foot

• can do a percutaneous angioplasty
• alternative is open bypass surgery

Question 15

What is an orthopaedic surgeon needed for in management of diabetic foot disease?

Answer 15

Either to

• correct abnormally shaped feet
• or to help amputate lost tissue/toes

Question 16

What is a chiropodist/podiatrist needed for in management of diabetic foot disease?

Answer 16

To help prevent problems

To remove callus around ulcers to help healing

Question 17

What is an orthotist needed for in management of diabetic foot disease?

Answer 17

Orthotists design and build specialist footwear for the patient either to prevent ulcers or to prevent worsening of the ulcers while they are healing

Question 18

What are the options for management of foot ulceration?

Answer 18

Relief of pressure

• bed rest (however, risk of DVT, heel ulceration)
• redistribution of pressure/total contact cast

Antibiotics, possibly long-term (e.g. infection in bone, osteomyelitis)

Debridement (removal of dead tissue/toe/foot)

Revascularisation

• angioplasty
• arterial bypass surgery

Amputation

Question 19

What is Charcot’s foot?

Answer 19

“Jigsaw of bones all jumbled up”
- Patient has neuropathy and don’t feel their foot and don’t put pressure down appropriately

Results in destruction of joints which then leads to all the bones being totally disturbed producing abnormal pressure in the foot

Question 20

What is osteomyelitis?

Answer 20

Infection of bone which leads to similar symptoms/signs as Charcot’s foot

Question 21

What are the features of the foot in osteomyelitis and Charcot’s foot?

Answer 21

Osteomyelitis

• hot red foot with ulcer
• MRI shows marrow oedema in forefoot and hindfoot near the ulcer (inflammation around site of infection)

Active Charcot’s foot

• hot red foot with NO ulcer
• MRI shows marrow oedema in midfoot subchrondral

Both will show abnormal articulation of bones in the foot
- point here is that both diseases are difficult to distinguish between and Charcot’s is a result of diabetic neuropathy over a long period of time where the neuropathy, and resulting uneven distribution of pressure, has been left untreated

Question 22

What are the conclusions about diabetic foot disease?

Answer 22

• Common and major burden to our patients
• Neuropathy, peripheral vascular disease (PVD), infection and other factors contribute
• Management takes time

Question 23

What is a new way of predicting risk of blindness and amputation in diabetic patients?

Answer 23

Used risk prediction equations to estimate risk of blindness and amputation
- took into account T1/T2D, yrs since diagnosis, smoking, ethnicity, deprivation, HbA1c levels, sbp, Cholesterol ratio, atrial fibrillation, heart failure, coronary vascular disease, renal disease, rheumatoid arthritis, and presence of retinopathy

All of these showed clear risk prediction conclusions regarding blindness and amputation