Diabetic Foot

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Pathophysiology & Risk Factors - Triad Trouble

  • Core Pathophysiological Triad:
    • Neuropathy: Sensory (Loss Of Protective Sensation - LOPS), motor (muscle imbalance → deformities like claw toes, Charcot), autonomic (anhidrosis → dry, cracked skin).
    • Angiopathy (PAD): Atherosclerosis → ↓ blood flow, ↓ oxygen & nutrient delivery, impaired wound healing. Affects distal vessels.
    • Immunopathy: Impaired leukocyte function, ↓ chemotaxis & phagocytosis, blunted inflammatory response → ↑ infection susceptibility.
  • Key Risk Factors:
    • Uncontrolled DM (HbA1c > 7%)
    • DM duration > 10 years
    • Previous DFU/amputation
    • Structural foot deformity
    • Limited joint mobility
    • Poor footwear, smoking
    • Visual impairment, nephropathy

⭐ Peripheral neuropathy is the primary factor in the development of diabetic foot ulcers.

Clinical Assessment & Diagnosis - Spotting the Signs

  • History: DM duration, glycemic control, neuropathy symptoms (pain, numbness), claudication, prior ulcers.
  • Examination:
    • Inspect: Deformities (Charcot, claw/hammer toes), calluses, ulcers (site, size, depth, base, discharge), skin (dry, fissures, hair loss, infection signs).
    • Palpate: Skin temperature, tenderness, pulses (DP, PT), Capillary Refill Time.
    • Neuropathy: 10g Semmes-Weinstein Monofilament (SWMT), 128Hz tuning fork (vibration).
    • Vascular: Ankle-Brachial Index (ABI).

      ⭐ An Ankle-Brachial Index (ABI) < 0.9 suggests Peripheral Arterial Disease (PAD).

  • Key Investigations:
    • X-ray: Osteomyelitis, gas, foreign body, Charcot.
    • MRI: Gold standard for osteomyelitis, deep abscess.
    • Doppler Ultrasound: Assesses arterial flow.
    • Wound Culture: For targeted antibiotics.

Focused Foot Examination for Diabetic Patients

Classification & Charcot Foot - Grading the Grief

Diabetic Foot Ulcer Classification:

  • Wagner Classification: Key system for severity.
    • Grade 0: Intact skin, may have bony deformity (pre-ulcerative).
    • Grade 1: Superficial ulcer (skin only).
    • Grade 2: Ulcer extending to ligament, tendon, joint capsule, or deep fascia (no bone/abscess).
    • Grade 3: Deep ulcer with abscess, osteomyelitis, or septic arthritis.
    • Grade 4: Gangrene of a portion of the forefoot or heel.
    • Grade 5: Extensive gangrene of the entire foot.
  • University of Texas (UT) Classification:
    • Matrix: Combines ulcer depth (Grades 0-III) with presence of Infection and/or Ischemia (Stages A-D).

Charcot Neuroarthropathy:

  • Progressive, non-infectious, destructive process affecting bones, joints, and soft tissues, typically in individuals with neuropathy.
  • Acute phase: Presents as a red, hot, swollen foot; often misdiagnosed as infection.
  • Eichenholtz Classification (Modified):

⭐ Wagner Grade 3 ulcer involves deep infection with abscess, osteomyelitis, or septic arthritis.

Management & Prevention - Healing & Halting

  • Multidisciplinary Team: Key.
  • Wound Care:
    • Sharp debridement.
    • Moist wound dressings (hydrocolloids, alginates).
    • NPWT for select wounds.
  • Infection Control:
    • Mild: Oral antibiotics.
    • Mod/Severe: IV Abx, surgical debridement.
    • Deep tissue cultures.
  • Offloading (Key for Neuropathic Ulcers):

    ⭐ Total Contact Casting (TCC) is the gold standard for offloading neuropathic plantar ulcers.

    • Alternatives: Removable Cast Walkers (RCW), therapeutic shoes.
  • Vascular Management:
    • Assess: ABI < 0.9 or > 1.3 (calcification) needs vascular studies.
    • Revascularization for PAD.
  • Surgical Interventions:
    • Debridement, I&D.
    • Charcot reconstruction.
    • Amputations (minor/major) last resort.
  • Prevention (Halting Progression):
    • Glycemic control (HbA1c < 7%).
    • Education: Daily foot inspection, hygiene, nail care.
    • Therapeutic footwear, orthotics.
    • Podiatric care.
    • 📌 Mnemonic: "FOOT CARE" (Footwear, Observe daily, Offloading, Test sensation, Control sugar, Annual check-up, Refer early, Educate).

TCC and TCS Cast Layers for Diabetic Foot Ulcers

High‑Yield Points - ⚡ Biggest Takeaways

  • Diabetic Foot triad: neuropathy (sensory loss), angiopathy (poor circulation), and immunodeficiency.
  • Charcot neuroarthropathy: progressive destruction causing rocker-bottom foot deformity.
  • Wagner classification (Grades 0-5) is essential for ulcer staging.
  • Management pillars: strict glycemic control, wound debridement, effective offloading (e.g., Total Contact Cast), and targeted antibiotics.
  • Always assess for Peripheral Vascular Disease; revascularization may be needed.
  • Osteomyelitis is a common, severe complication requiring prompt, aggressive treatment.
  • Prevention is key: patient education, daily foot inspection, and appropriate footwear.

Practice Questions: Diabetic Foot

Test your understanding with these related questions

A 60-year-old person who completed treatment for leprosy many years ago now presents with a punched-out, painless ulcer on the sole of his foot. What is the most appropriate management?

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Flashcards: Diabetic Foot

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Conservative treatment of Hallux valgus involves _____

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Conservative treatment of Hallux valgus involves _____

putting fillers between fingers

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