II. Differential Diagnosis

III. Findings: Red Flags suggestive of Foot Osteomyelitis

  1. Sausage toe (swollen, deformed red toe)
  2. Bone Visualized or Probe-to-Bone Test positive
  3. Skin ulcer with red flags
    1. Infected ulcer with ESR >70 mm/h or unexplained Leukocytosis
    2. Non-healing ulcer despite several weeks of wound care and non-weight bearing
    3. Non-healing ulcer over bony prominences despite wound care
    4. Ulcer with underlying bony XRay changes
    5. Ulcer area >2 cm^2
    6. Ulcer depth >3 mm

IV. Classification: Diabetic Foot Ulcer

V. Grading: Diabetic Wound Severity

  1. Not infected
    1. Wound without purulence or inflammation
  2. Mild Infection
    1. Wound with purulence and inflammation
    2. Localized infection that does not extend more than 2 cm beyond ulcer margins
  3. Moderate Infection
    1. Regional infection extending more than 2 cm beyond ulcer margins
    2. Ascending lymphangitis with deep infection
  4. Severe Infection
    1. Sepsis

VI. Evaluation

  1. Evaluate foot neurovascular status
  2. Bone Visualized or Probe-to-Bone Test positive
    1. Treat as presumptive Osteomyelitis
  3. Osteomyelitis XRay consistent with Osteomyelitis
    1. Treat as presumptive Osteomyelitis
  4. Osteomyelitis XRay not consistent with Osteomyelitis
    1. Severe Peripheral Neuropathy or high suspicion
      1. Obtain Osteomyelitis Bone Scan or Osteomyelitis Bone MRI
        1. Positive: Treat as presumptive Osteomyelitis
        2. Negative: Treat as Soft Tissue infection
    2. Lower suspicion for Osteomyelitis
      1. Treat as Soft Tissue Infection

VII. Management: General

  1. Wound Care
    1. Cleanse and debride wound
    2. Unload the wound (e.g. non-weight bearing)
    3. Consider Wound Healing agents
    4. Evaluate foot wear
    5. Obtain wound culture and Gram Stain
  2. Mild to moderate infections
    1. Choose parenteral or oral agents as below
    2. Reevaluate every 2-3 days until improving
    3. Treat as severe infection if lack of improvement
  3. Severe infections
    1. Hospitalize and treat with parenteral agents
    2. Obtain deep wound culture (consider bone biopsy and culture)
    3. Reevaluate twice daily
    4. Consider orthopedic surgery for bone biposy or resection
    5. Consider vascular surgery for revascularization considerations
    6. Consider hyperbaric oxygen or Granulocyte stimulating factors

VIII. Management: Antibiotic Course

  1. Soft tissue infection
    1. Mild Foot Infection: 1-2 week total course
    2. Moderate Foot Infection: 2-4 week total course
    3. Severe Foot Infection: 2-4 week total course
  2. Bone infection
    1. Post-amputation without residual infection: 2-5 days of antibiotics
    2. Residual infected viable bone: 4-6 week total course
    3. Residual infected dead bone: 8-12 week total course

IX. Management

  1. See Diabetic Foot Infection for initial antibiotic coverage
  2. Try to obtain bone culture prior to starting antibiotics in Osteomyelitis

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