Diabetic Foot Ulcer

Anatomy of foot – forefoot, midfoot, hindfoot

Wegener's Classification
Type 0 - No ulcer 
Type 1 - Superficial ulcer
Type 2 - Deep ulcer
Type 3 - Osteomyelitis with ulcer / abscess
Type 4 - Localised / partial foot gangrene
Type 5 - Gangrene of entire foot


Texas Classification

1. Stages
   1. Stage A: No infection or ischemia
   2. Stage B: Infection present
   3. Stage C: Ischemia present
   4. Stage D: Infection and ischemia present
2. Grading
   1. Grade 0: Epithelialized wound
   2. Grade 1: Superficial wound
   3. Grade 2: Wound penetrates to tendon or capsule
   4. Grade 3: Wound penetrates to bone or joint

Pathophysiology – neuropathy (1/3), PVD (1/3), mixed (1/3)

1.       Neuropathy

A.      Sensory

                                                               i.      Symmetrical sensori polyneuropathy

§  ↓ sensation (esp vibration)

§  Distil numbness “Glove and stocking distribution”

àLoss of protective sensation of feet

à ↑ risk of ulceration & infection

§  Neuropathic pain, often worse at night

                                                             ii.      Neurological exam

§  Vibration: tuning fork 128 Hz

§  Pressure & touch: Cotton wool (light), Semmes Weistein Monofilament (5.07/10gm)

§  2 point discrimination

§  Pain: Pinprick

§  Deep tendon reflex

a.       Ankle  S1 (absent)

b.      Knee   L4

§  Clonus

§  Barbinski test

                                                            iii.      Tx: aspirin/PCM à amitryptyline à gabapentine

B.      Motor

                                                               i.      Lumbosacral radiculopathy, plexopathy, proximal crural neuropathy

à painful wasting of quadriceps

C.      Autonomic - Loss of sympathetic innervations

                                                               i.      Vasodilatation of vessel

a. Hb into 3^rd space à Iron deposition à hyperpigmentation

b. Venous stasis à oedema

                                                             ii.      ↓ sweating

§  Callous

§  Heel fissure

§  Cracking of skin

§  Thickened nail

2.       PVD  - microangiopathy

Assessment of healing potential

                                  i.            Droppler segmental artery pressure

                                ii.            ABSI – ankle-brachial indices. N 1.1, <0.9 abnormal

ABSI (Ankle Brachial Systolic Index)

- quantitative measurement of vascularity

- formula, ABPI = Ankle pressure/ brachial pressure

- should also mention biphasic/traphasic

- importance: tendency of wound healing 

    Normal : 0.7-1.1

    Poor wound healing <0.7

    Atherosclerosis >1.1

                               iii.            Toe pressure measurement

·         Toe P >40mmHg            >85% healing

·         Toe P < 20mmHg           <10% healing

                              iv.            TcPO₂ (Transcutaneous oxygen tension )

·         <10mmHg         Non-healing

·         >30mmHg         Healing

Further work-up (if above Ix abnormal)

                                 i.            Arteriography

                               ii.            DSA (digital subtraction angiography)

                              iii.             MRA (magnetic resonance angiography)

Principles of Treatment

Acute

1.       Wound debridement

2.       Wound dressing

3.       Treatment of infection 

       Antibiotics - to cover polymicrobial

             IV unasyn (ampicillin + sulbactam) 1.5g TDS

4.       Anti-pyrexia

Long term

5.       DM control

6.       Vascular managements

7.       Management of co-morbidities

8.       Surgical management e.g. amputation

9.       Prevent recurrence

a.       ↓ plantar pressure

b.      Proper footwear

c.       Early identification of new lesion

d.      Foot hygiene