Diabetic Foot Osteomyelitis

Diabetic Foot Osteomyelitis, Osteomyelitis Management in Diabetes Mellitus, Suspected Osteomyelitis in Diabetes Mellitus, Diabetes Mellitus Associated Osteomyelitis, Osteomyelitis due to Type 1 Diabetes Mellitus, Osteomyelitis due to Type 2 Diabetes Mellitus

See Also

Risk Factors

Differential Diagnosis

See Osteomyelitis

Findings
Red Flags suggestive of Foot Osteomyelitis

Sausage toe (swollen, deformed red toe)
Bone Visualized or Probe-to-Bone Test positive
Skin Ulcer with red flags
1. Infected ulcer with ESR >70 mm/h, CRP >8 mg/dl or unexplained Leukocytosis
  1. Lavery (2019) Clin Orthop Relat Res 477(7):1594-1602 +PMID: 31268423 [PubMed]
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

Classification
Diabetic Foot Ulcer

Grading
Diabetic Wound Severity

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

Evaluation

Evaluate foot neurovascular status
Bone Visualized or Probe-to-Bone Test positive
1. Treat as presumptive Osteomyelitis
Osteomyelitis XRay consistent with Osteomyelitis
1. Treat as presumptive Osteomyelitis
Osteomyelitis XRay not consistent with Osteomyelitis
1. Severe Peripheral Neuropathy, high markers (e.g. ESR>60-70, CRP>8) 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

Management
General

Background
1. Chronic diabetic Osteomyelitis is typically a slow, indolent infection without systemic toxicity
  1. Contrast with Acute Osteomyelitis from hematogenous spread (typically in ill appearing children)
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
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
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

Management
Antibiotic Course

See Diabetic Foot Infection for initial Antibiotic coverage
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
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

Management

See Diabetic Foot Infection for initial Antibiotic coverage
Try to obtain bone culture prior to starting Antibiotics in Osteomyelitis

References