1. Diabetic Feet

2. Why do you need to know about
diabetic feet?
 Foot complications are the most common reason
for hospitalisation of diabetic patients
 Diabetes is the leading risk factor for major
amputation
 Half of all diabetics with a major amputation lose
their other leg within five years
 One year survival for diabetic patients with critical
leg ischaemia is around 50%
 Neuropathy, ischaemia and infection leads to
ulceration, necrosis and gangrene

3. Neuropathy
 Neuropathy affects 80% diabetics
presenting with foot lesions
 Sensory: deprives patient of pain reflexes
 Motor: intrinsic muscles of the foot leading to
clawing of toes
 Autonomic: shunting of blood, anhidrosis,
dehydration, fissuring and less elastic skin,
mineral washout from bones

4.  Sesamoid bones move forward so weight borne on
metatarsal heads, especially the second metatarsal
 Eventually the ankle thrown into equinus and the bones
collapse: Charcot’s foot
 Load bearing then leads to pressure ulceration, made
worse by footwear

6. Ischaemia
 Combination of proximal occlusive atherosclerosis:
 Tibial vessels more severely affected in diabetes
 And distal microcirculatory failure:
 Failure of endothelium to respond to vasodilators, e.g. NO
 Hyperglycaemia, insulin resistance
 Changes in basement membrane by products of glycation
 Impaired leucocyte migration
 Loss of local axon-mediated vasodilation (nuropathy)

8. Infection
 Can arise insidiously
 Sole of foot, nailbed
 Compartments of the foot constrain pus to track
backwards – not seen by patient or felt in presence of
neuropathy
 Obtunded immune response and hyperglycaemia: ideal
breeding ground for synergistic infections of aerobic
and anaerobic bacterial infections
 Beware gas gangrene

10. Take a history
 Symptoms – especially pain
 Main cause for acute deterioration?
 Ischaemia/neuropathy/infection
 Pre-existing arterial disease?
 Pre-existing neuropathy?
 What is realistic goal of therapy?

11. Examination
 Source for infection?
 Look for osteomyelitis
 Sausage shaped swelling of whole digit
 Chronic discharging sinus
 Easy subluxation of joints
 Visible or palpable bone on probing
 Neuropathy – check with cotton wool/nylon brush
 Ulcer – does it bleed? i.e. has blood supply
 Pulses – classically no foot pulses felt

12. Adjuncts to examination
 ABPI – unreliable as incompressible pedal arteries
 Doppler signal – monophasic implies significant
proximal artery occlusion

13. Imaging
 Duplex ultrasound
 MR Angiography
 Angiography –
 beware concurrent renal impairment
 contrast induced nephropathy

14. Treatment
 Analgesia
 Hydration
 Oxygen
 Control of diabetes
 High dose antibiotics IV – Pencillin and Metronidazole.
Consider MRSA.
 Wound debridement and toilet
 Simple dressings: hydrogel, maggots?
 VAC dressings for larger wounds

15. Revascularisation
 Discuss at MDT
 Distal angioplasty or bypass
 Is it possible, i.e. extent of disease, presence of suitable
vein, infection (MRSA)
 Distal gangrene – local amputation inc. metatarsal head
 Web space gangrene – ray amputation
 Major amputations can be life saving
Amputation

16. Summary

17. Key points
 Prevention is better than cure:
 Diabetic foot clinics
 Patient education
 Admit patients under medical care for diabetic control
 Beware contrast related renal failure
 MDT approach: vascular surgeons, radiology,
endocrine physicians, renal medicine, OT, physio and
rehab centres