Diabetic Foot Pathway: From Callus to Amputation

The Diabetic Foot Pathway:<br>Callus to Amputation

Understanding the Progression, Prevention & Multidisciplinary Management

For Healthcare Professionals — Nurses, Podiatrists & GPs

Understanding the Diabetic Foot

15%

of patients with diabetes will develop a foot ulcer during their lifetime.

85%

of major lower extremity amputations are preceded by a non-healing foot ulcer.

#1

leading cause of non-traumatic lower-extremity amputations globally.

The Core Triad of Risk

Neuropathy

Ischemia

Infection

Foot<br>Ulcer

The interplay of loss of protective sensation, arterial insufficiency, and susceptibility to infection.

The Pathophysiology: Why Feet Fail in Diabetes

Peripheral Neuropathy

Loss of protective sensation (LOPS) masking injury

Motor neuropathy causing structural foot deformity

Autonomic neuropathy causing dry skin & fissures

Peripheral Arterial Disease

Significantly reduced blood flow to extremities

Impaired supply of vital oxygen and nutrients

Poor wound healing & increased risk of ischemia

Immunopathy

Impaired neutrophil and phagocytic cell function

Poor local inflammatory and infection response

Exacerbated risk under uncontrolled hyperglycemia

Callus: The Starting Point

What is callus?

Thickened skin resulting from repetitive pressure and friction.

Key Locations

Metatarsal heads, the heel, and the toes.

Why it matters in diabetes

Masks underlying ulceration

Increases plantar pressure by up to 30%

Acts as a pre-ulcerative lesion

Clinical Assessment

Inspect feet regularly and ensure prompt professional debridement.

Prevention

Implement optimal offloading and targeted appropriate footwear.

Diabetic Foot Ulcers: Classification & Assessment

Wagner Grade System (0-5)

Pre/post<br>ulcer

Superficial<br>ulcer

Deep to tendon<br>or capsule

Deep with<br>osteomyelitis

Partial<br>gangrene

Full foot<br>gangrene

Key Assessment Pillars

Also see: SINBAD & University of Texas Systems

Wound Size

Ulcer Depth

Infection Signs

Vascularity

Sensation

Infection in the Diabetic Foot

Breakdown of the skin barrier (typically via chronic ulceration)

Frequently polymicrobial (involving multiple bacterial strains)

Clinical Tip: Patients may lack classic signs (e.g., pain) due to peripheral neuropathy.

Look for: localized redness, warmth, swelling, or purulent discharge (pus).

A positive probe-to-bone test strongly suggests underlying osteomyelitis.

Fever &nbsp; • &nbsp; Systemic Sepsis &nbsp; • &nbsp; Crepitus &nbsp; • &nbsp; Rapidly Spreading Cellulitis

Vascular Assessment & Ischemia

Timely vascular assessment is crucial in evaluating Diabetic Foot Ulcers (DFU) to determine healing potential and prevent lower extremity amputation.

Osteomyelitis: Bone Deep

Definition & Mechanism

<b>Bone infection</b> — a limb-threatening complication.<br>It occurs predominantly via <b>contiguous spread</b> from soft tissue in Diabetic Foot Ulcers.

Diagnosis

<ul style='margin: 0; padding-left: 20px;'><li style='margin-bottom: 15px;'><b>Probe-to-bone test</b> <span style='font-size: 22px; color: #D16D54;'>(sensitivity 89%)</span></li><li style='margin-bottom: 15px;'><b>Plain X-ray</b> <span style='font-size: 22px; color: #888888;'>(late changes)</span></li><li style='margin-bottom: 15px;'><b>MRI</b> <span style='font-size: 22px; color: #D16D54;'>(gold standard)</span></li><li style='margin-bottom: 0;'><b>Bone biopsy</b></li></ul>

Treatment Strategy

<ul style='margin: 0; padding-left: 20px;'><li style='margin-bottom: 15px;'><b>Prolonged antibiotics</b> <span style='font-size: 22px; color: #D16D54;'>(6 weeks+)</span></li><li style='margin-bottom: 15px;'><b>Surgical debridement</b></li><li style='margin-bottom: 0;'><b>Possible ray amputation</b></li></ul>

Early diagnosis is critical to avoid major amputation.

The Multidisciplinary<br>Team Approach

A collaborative, patient-centered model for managing diabetic foot disease covering prevention to surgical intervention.

Core MDT Members

Podiatrist

Debridement, offloading & wound care

Diabetologist

Glycaemic control & systemic management

Vascular Surgeon

Revascularization & tissue perfusion

Orthopaedic Surgeon

Bone/joint intervention & amputation

Infectious Disease

Microbiology & antibiotic stewardship

Wound Care Nurse

Specialist dressings & daily monitoring

Orthotist

Custom footwear & offloading devices

General Practitioner

Care coordination & primary prevention

Amputation: When & Why

Minor Amputation

Toe, ray, transmetatarsal

Major Amputation

Below-knee, above-knee

Pre & Post-Amputation Care

Uncontrollable infection

Critical ischemia

Non-healing wound

Patient choice

Aim for most distal level possible

Vascular assessment before surgery

Stump healing considerations

Psychological Support

Physiotherapy

Prosthetics

Rehabilitation

Prevention: Breaking the Cycle

Regular Screening

Annual foot screening for all diabetic patients, and 3-monthly reviews for those at high risk.

Patient Education

Teaching essential foot care, appropriate footwear choices, and the rule to never walk barefoot.

Glycaemic Control

Maintaining strict HbA1c targets to minimise neuropathy and peripheral vascular complications.

Pressure Offloading

Using total contact casting and therapeutic footwear to safely relieve pressure areas.

Early Referral

Establishing rapid pathways ensuring any new ulcer is seen by specialist podiatry within 24 hours.

Risk Stratification

Categorising patients actively into NICE/IWGDF low, moderate, high, or active disease statuses.

Early detection and prompt action saves limbs and lives.

Key Takeaways

<strong style="color: #222222;">Callus is not benign</strong> &mdash; it signals high pressure and risk of ulceration

<strong style="color: #222222;">Neuropathy, ischemia and infection</strong> are the triad driving diabetic foot disease

<strong style="color: #222222;">Classify every ulcer</strong> &mdash; Wagner or SINBAD grading guides management

<strong style="color: #222222;">Infection can be silent</strong> in diabetics &mdash; always probe, assess, and image

<strong style="color: #222222;">MDT coordination is essential</strong> at every stage of the pathway

<strong style="color: #222222;">Prevention and early referral</strong> are the most powerful tools we have

References: <span style="color: #555555; font-weight: 400;">NICE NG19 &nbsp;&bull;&nbsp; IWGDF Guidelines 2023 &nbsp;&bull;&nbsp; Diabetes UK</span>