Definition:

The term diabetic foot refers to a spectrum of foot disorders ranging from ulceration to gangrene occurring in diabetic people as a result of peripheral neuropathy or ischaemia, or both.

Key Points:

• Prevention is everything in diabetic feet.
• All infections should be treated aggressively to reduce the risk of tissue loss.
• Treat major vessel POVD as normal-improve ‘inflow’ to the foot.

Pathophysiology:

Three distinct processes lead to the problem of the diabetic foot.

• Ischaemia caused by macro- and microangiopathy.
• Neuropathy: sensory, motor and autonomic.
• Sepsis: the glucose-saturated tissue promotes bacterial growth.

Clinical features:

Neuropathic features -

• Sensory disturbances.
• Trophic skin changes.
• Plantar ulceration.
• Degenerative arthropathy (Charcot’s joints).
• Pulses often present.
• Sepsis (bacterial/fungal).

Ischaemic features -

• Rest pain.
• Painful ulcers over pressure areas.
• History of intermittent claudication.
• Absent pulses.
• Sepsis (bacterial/fungal).

Investigations:

• Non-invasive vascular tests: ABI, segmental pressure, digital pressure. ABI may be falsely elevated due to medial sclerosis.
• X-ray of foot may show osteomyelitis.
• Arteriography.

Essential Management:

Should be undertaken jointly by surgeon and physician as diabetic foot may precipitate diabetic ketoacidosis.

Prevention -

Do

• Carefully wash and dry feet daily.
• Inspect feet daily.
• Take meticulous care of toenails.
• Use antifungal powder.

Do not

• Walk barefoot.
• Wear ill-fitting shoes.
• Use a hot water bottle.
• Ignore any foot injury.

Neuropathic disease -

• Control infection with antibiotics effective against both aerobes and anaerobes.
• Wide local excision and drainage of necrotic tissue.
• These measures usually result in healing.

Ischaemic disease-

• Formal assessment of the vascular tree by angiography and reconstitution of the blood supply to the foot (either by angioplasty or bypass surgery) must be achieved before the local measures will work.
• After restoration of blood supply treat as for neuropathic disease.