What is the optimal management of a plantar ulcer in an adult with diabetes, peripheral neuropathy, and possible peripheral arterial disease?

Optimal Management of Plantar Ulcers in Diabetic Patients

The cornerstone of plantar ulcer treatment is aggressive pressure offloading with a non-removable knee-high device (total contact cast or irremovable walking boot), combined with sharp debridement, infection control, and vascular assessment to determine need for revascularization. 1

Immediate Vascular Assessment

Before initiating any treatment, assess perfusion status to determine if revascularization is needed:

• Measure ankle-brachial index (ABI), ankle pressure, and toe pressure in all patients 2, 1
• If ankle pressure <50 mmHg or ABI <0.5, obtain urgent vascular imaging and consider immediate revascularization 1
• If toe pressure <30 mmHg or TcpO2 <25 mmHg, revascularization should also be considered 1
• If ulcer shows no healing after 6 weeks despite optimal management, pursue revascularization regardless of initial vascular test results 1

Primary Treatment: Pressure Offloading

For Uncomplicated Neuropathic Plantar Ulcers

Use a non-removable knee-high offloading device as first-line treatment 1:

• Total contact cast (TCC) is the gold standard 1
• Alternatively, use a removable walking boot rendered irremovable 1
• Non-removable devices are superior to removable devices because they eliminate non-adherence, which is the primary cause of treatment failure 1, 3
• Multiple RCTs demonstrate faster healing rates and higher healing percentages with non-removable versus removable devices 1

If non-removable devices are contraindicated, use a removable offloading device as second choice 1

If offloading devices are unavailable, use felted foam combined with appropriate footwear as third choice 1

For Plantar Ulcers with Mild Infection or Mild Ischemia

Consider using a non-removable knee-high device, as evidence shows these may cause large increases in healing even with mild infection present (adjusted OR 2.53) 1

For Plantar Ulcers with Moderate Infection/Ischemia

Use a removable offloading device rather than non-removable 1

• Removable devices allow for frequent wound inspection and dressing changes needed with moderate complications 1

For Plantar Ulcers with Severe Infection or Severe Ischemia

Primarily address the infection and/or ischemia first, then use removable offloading based on individual factors 1

• Severe infection requires urgent surgical debridement and parenteral broad-spectrum antibiotics 1
• Severe ischemia requires urgent revascularization 1

Essential Wound Care Components

Sharp Debridement

Perform immediate sharp debridement of all necrotic tissue and surrounding callus 1:

• Repeat debridement as frequently as needed (typically weekly) 1
• This can usually be done without anesthesia in neuropathic ulcers due to sensory loss 2
• Debridement is critical and cannot be compensated for by other treatments 1

Wound Dressing Selection

Select dressings to control excess exudate and maintain a moist wound environment 1

Inspect the ulcer frequently to assess healing progress and identify signs of infection or biofilm 1

Infection Management

For superficial infection (mild):

• Cleanse and debride all necrotic tissue 1
• Start empiric oral antibiotics targeting S. aureus and streptococci 1, 2

For deep infection (moderate to severe):

• Urgently evaluate for surgical intervention to remove necrotic tissue, drain abscesses, and debride infected bone 1
• Initiate empiric parenteral broad-spectrum antibiotics covering gram-positive, gram-negative, and anaerobic bacteria 1
• Assess for peripheral arterial disease and consider urgent revascularization 1
• Adjust antibiotics based on culture results and clinical response 1

Adjunctive Therapies

Negative Pressure Wound Therapy

Consider negative pressure therapy to help heal post-operative wounds after surgical debridement 1

Hyperbaric Oxygen Therapy

In patients with nonhealing diabetic foot ulcers after revascularization, hyperbaric oxygen therapy may be considered as adjunctive treatment 1

• This has limited evidence and should only be used after standard treatments are optimized 1

Surgical Offloading for Refractory Ulcers

If non-surgical offloading fails for plantar metatarsal head ulcers, consider:

• Achilles tendon lengthening combined with offloading device 1
• Metatarsal head resection combined with offloading device 1

For neuropathic plantar or apex ulcers on digits 2-5 with flexible toe deformity, perform digital flexor tenotomy 1:

• This has strong evidence as first-line treatment for these specific ulcers 1
• Recent RCT shows clear benefit over conservative care 1

Critical Pitfalls to Avoid

Inadequate offloading is the primary reason for treatment failure 2, 3:

• Partial offloading is insufficient 2
• Removable devices fail when patients don't wear them consistently 1, 3
• Most clinics use less effective methods despite strong evidence for non-removable devices 3

Delayed recognition of ischemia leads to treatment failure:

• Even optimal wound care cannot compensate for inadequately treated ischemia 1
• Always assess vascular status before assuming purely neuropathic etiology 2

Failure to address infection promptly leads to osteomyelitis and amputation:

• Assess for infection at every visit 2
• Deep infections require urgent surgical intervention, not just antibiotics 1

Expected Healing Timeline

With adequate offloading and no ischemia or infection, noninfected neuropathic plantar forefoot ulcers should heal in 6-8 weeks 3, 4

If not healing after 6 weeks despite optimal management, reassess for:

• Inadequate offloading (most common cause) 3
• Unrecognized ischemia requiring revascularization 1
• Persistent infection or osteomyelitis 1