How to offload a diabetic foot ulcer effectively?

How to Offload a Diabetic Foot Ulcer

For a diabetic patient with a neuropathic plantar forefoot or midfoot ulcer, use a non-removable knee-high offloading device (either a total contact cast or non-removable walker) as your first-line treatment. 1

First-Line Offloading: Non-Removable Knee-High Devices

Use a non-removable knee-high offloading device as the gold standard for healing neuropathic plantar forefoot and midfoot ulcers. 1 This recommendation carries a strong GRADE rating with moderate certainty of evidence, meaning the benefits substantially outweigh the harms. 1

Device Selection

You have two equally effective options for non-removable offloading 1:

• Total Contact Cast (TCC): The traditional "gold standard" that provides complete immobilization and pressure redistribution 2
• Non-removable knee-high walker: A prefabricated device rendered irremovable (typically by wrapping with cohesive bandage) 1

Choose between these based on local resources, your expertise in application, and patient-specific factors (body habitus, skin integrity, ability to return for cast changes). 1 Both achieve similar healing rates when properly applied. 1

Why Non-Removable Devices Work

The key advantage is eliminating patient non-adherence—patients cannot remove the device, ensuring continuous offloading during all weight-bearing activities. 3 Studies show healing rates of 75-95% with non-removable devices compared to only 35% with removable options. 4, 5

Important Contraindications

Do not use non-removable devices if the patient has 1:

• Severe infection (moderate to severe)
• Severe ischemia (ankle-brachial index <0.5 or toe pressure <30 mmHg)
• Significant edema requiring frequent monitoring
• Fragile skin at high risk for pressure injury
• Inability to return for weekly monitoring

Second-Line: Removable Offloading Devices

If non-removable devices are contraindicated or not tolerated, use a removable knee-high or ankle-high offloading device (such as a removable cast walker or diabetic offloading boot). 1

Critical Patient Education

You must strongly emphasize that the patient wear the device during ALL weight-bearing activities, including nighttime bathroom trips. 1 The primary failure mode of removable devices is non-adherence—patients remove them for comfort, defeating the purpose. 3

Third-Line: Felted Foam with Appropriate Footwear

When offloading devices are unavailable or unaffordable, use felted foam padding in combination with appropriately fitting footwear. 1 This is the minimum acceptable offloading intervention, though significantly less effective than device-based offloading. 1

What NOT to Do

Never allow patients to use conventional shoes or standard therapeutic footwear alone for ulcer healing. 1 This carries a strong recommendation because these provide inadequate pressure relief and will delay or prevent healing. 1

Surgical Offloading for Refractory Ulcers

If non-surgical offloading fails after 6-8 weeks of appropriate treatment, consider surgical intervention 3:

For Plantar Metatarsal Head Ulcers:

• Achilles tendon lengthening (strongest evidence, moderate certainty) 1
• Metatarsal head resection (low certainty evidence) 1
• Metatarsal osteotomy for metatarsal heads 2-5 (very low certainty) 1

For Hallux Ulcers:

• Joint arthroplasty (low certainty evidence) 1

For Lesser Toe Ulcers (digits 2-5):

Perform digital flexor tenotomy for plantar or apex ulcers secondary to flexible toe deformity. 1 This carries a strong recommendation with moderate certainty evidence. 1

Modified Approach for Complicated Ulcers

Mild Infection or Mild Ischemia:

Consider using a non-removable knee-high device, but monitor more frequently (every 2-3 days initially) for signs of deterioration. 1

Moderate Infection OR Moderate Ischemia:

Use a removable offloading device to allow daily wound inspection and dressing changes. 1

Severe Infection OR Severe Ischemia:

Do not use knee-high offloading devices. 1 Focus on treating the infection/ischemia first with appropriate antibiotics, debridement, or revascularization. Use minimal offloading with appropriate footwear until the complication resolves. 1

Common Pitfalls to Avoid

Monitor for complications of non-removable devices including new pressure ulcers (1-15% incidence), falls due to gait asymmetry, and knee/hip pain from leg length discrepancy. 1 Weekly cast changes allow inspection and early detection. 2

Ensure proper casting technique with adequate padding over bony prominences and appropriate foot-device interface to prevent iatrogenic ulceration. 1 Poor technique negates the benefits and can cause harm. 4

Address underlying biomechanical abnormalities such as foot deformities, as these contribute to ulcer recurrence rates of 30-40% within the first year. 1 Plan for appropriate therapeutic footwear after healing. 3