Rutherford Becker Classification System

What is the Rutherford Becker classification system?

• Rutherford Becker classification system is a classification system for chronic limb ischemia.
• This system is based on the clinical and objective criteria
• The Fontaine and Rutherford Systems have been used to classify risk of amputation and likelihood of benefit from revascularization by subcategorizing patients into two groups: ischemic rest pain and tissue loss.

The Rutherford staging system for CLTI describes six clinical categories of lower extremity ischemia, from Rutherford 0 (R0) patients who are asymptomatic to R6 patients who have major tissue loss extending above the trans-metatarsal level, with a functional foot that is regarded as non-salvageable (Rutherford et al. 1997).

R6 patients are regarded in literature as severe CLTI patients with little to no revascularisation or pharmacological options as they have presented too late or are too advanced in their disease (Sprengers et al. 2010).

Ultimately, major amputation may be the only option. Amongst patients with CLTI, R6 patients have the highest major LEA and mortality rates despite undergoing the same treatment as R4 and R5 patients (Brodmann et al. 2020).

As R6 patients carry the worst clinical prognosis (Sprengers et al. 2010), it is important that these patients are prioritised in studies addressing lower limb revascularisation options and outcomes.

Clinical Categories of Chronic Limb Ischemia (Rutherford Becker Classification System)

GRADE	CATEGORY	CLINICAL DESCRIPTION	OBJECTIVE CRITERIA
0	0	Asymptomatic, not hemodynamically significant	Normal treadmill/stress test
I	1	Mild claudication	Completes treadmill test, ankle pressure after exercise <25-50 mm Hg less than blood pressure
	2	Moderate claudication	Between categories 1 and 3
	3	Severe claudication	Cannot complete treadmill test, ankle pressure after exercise <50 mm Hg
II	4	Ischemic rest pain	Resting ankle pressure <40 mm Hg, flat or barely pulsatile ankle or metatarsal pulse volume recording, toe pressure <30 mm Hg
	5	Minor tissue loss: nonhealing ulcer, focal gangrene with diffuse pedal edema	Resting ankle pressure <60 mm Hg, flat or barely pulsatile ankle metatarsal pulse volume recording, toe pressure <40 mm Hg
III	6	Major tissue loss: extending above transmetatarsal level, functional foot no longer salvageable	Same as category 5

Key Developments in 2024–2025

The 2024–2025 AHA/ACC PAD guideline continues to endorse the Rutherford–Becker Classification for chronic limb‐threatening ischemia (CLTI) staging, while emphasizing its complementary use with wound-focused systems (e.g., WIfI) and highlighting ongoing refinements to improve prognostic precision and multidisciplinary communication.

1. Guideline Reaffirmation and Integration (2024–2025)

The 2024 American Heart Association/American College of Cardiology Peripheral Artery Disease guideline reaffirms:

• Core Utility: Rutherford–Becker Classes 0–6 remain the standard for stratifying CLTI severity based on claudication, rest pain, and tissue loss.​
• Multimodal Framework: Strong recommendation to pair Rutherford–Becker staging with the WIfI (Wound, Ischemia, and foot Infection) score for patients presenting with tissue loss, enhancing amputation‐risk prediction and revascularization planning.​
• Diabetic Foot Specificity: For diabetic patients, combining Rutherford–Becker with Wagner or SINBAD classifications is advised to capture neuropathic vs. ischemic ulcer characteristics and guide advanced therapies (e.g., hyperbaric oxygen).​

2. Refinements in Objective Criteria

Recent studies have clarified and standardized hemodynamic thresholds:

• Claudication Grades (1–3):
  • Grade 1 (mild): Postexercise ankle pressure drop <25–50 mm Hg below resting.​
  • Grade 3 (severe): Unable to complete treadmill test, postexercise ankle pressure <50 mm Hg.​
• Rest Pain (Class 4): Resting ankle pressure <40 mm Hg or toe pressure <30 mm Hg with flat/barely pulsatile waveforms.​
• Minor vs. Major Tissue Loss (Classes 5–6):
  • Class 5: Minor nonhealing ulcer or focal gangrene; resting ankle pressure <60 mm Hg, toe pressure <40 mm Hg.​
  • Class 6: Major tissue loss above the transmetatarsal level with identical hemodynamic criteria as Class 5, denoting a non‐salvageable foot.

Integration into Global Vascular Guidelines

• The 2024 Global Vascular Guidelines renamed “critical limb ischemia” as chronic limb-threatening ischemia (CLTI) to emphasize tissue loss and infection risk alongside ischemia.
• Rutherford stages 4–6 align with the CLTI definition, though perfusion thresholds (ABI ≤0.40 or TP <30 mm Hg) remain recommended for risk stratification.^[2]

Endorsement by American and European Societies

• The 2024 AHA/ACC PAD guideline reaffirms Rutherford’s chronic and acute categories for guiding revascularization decisions. Class I (viable) limbs often receive medical therapy alone; Classes IIa/IIb prompt endovascular or surgical intervention; Class III undergoes primary amputation.^[3]
• The 2024 European Society for Vascular Surgery guidelines continue to pair Rutherford staging with ankle-brachial index (ABI) measurement and recommend combining Rutherford class with the WIfI (Wound, Ischemia, foot Infection) staging system to refine prognosis and intervention planning.^[4]

Integration with WIfI Classification System

A significant recent development involves the integration of Rutherford Becker staging with the Wound, Ischemia, and foot Infection (WIfI) classification system. The 2024 ACC/AHA guideline emphasizes that objective risk classification schemas—particularly WIfI—should be used to identify patients who would benefit from peripheral revascularization and to assess amputation risk.​

The WIfI system stratifies CLTI patients into four clinical stages based on three criteria:​

• Wound (W): ranging from no ulceration to extensive gangrene involving forefoot and/or midfoot
• Ischemia (I): assessed by ankle-brachial index, ankle systolic pressure, toe pressure, or transcutaneous oxygen pressure
• Foot Infection (fI): graded by degree of localized and/or systemic extension

What is Chronic or Critical limb ischemia?

• Critical limb ischemia (CLI) is a clinical syndrome of ischemic pain at rest or tissue loss, such as nonhealing ulcers or gangrene, related to peripheral artery disease.
• Critical limb ischemia (CLI) may be considered the most severe pattern of peripheral artery disease (PAD), being associated with a high risk of major amputation, cardiovascular events and death.
• CLI has a high short-term risk of limb loss and cardiovascular events. Noninvasive or invasive angiography help determine the feasibility and approach to arterial revascularization.
• A mortality rate of 20% within 6 months after the diagnosis and 50% at 5 years has been reported.
• Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease.
• It is defined by the presence of chronic ischemic rest pain, ulceration or gangrene attributable to the occlusion of peripheral arterial vessels.
• It is popular in the United States.
• This excessive mortality may be related to the systemic cardiovascular diseases, including coronary artery disease and cerebrovascular arterial disease. Furthermore, CLI is associated with peripheral complications such as ulceration, gangrene, infection and a high risk of lower limb amputation estimated in 10%–40% of patients at 6 months, especially in non-treatable patients

• The Rutherford-Becker Classification System helps clinicians determine the appropriate treatment options for peripheral arterial disease, ranging from lifestyle modifications and medical management for milder stages to more invasive interventions such as endovascular procedures or surgery for advanced stages.
• The classification system provides a framework for assessing the severity of PAD and helps guide decisions regarding the optimal management approach for individual patients.
• It’s important to note that the Rutherford-Becker Classification is one of several classification systems used in the evaluation and management of peripheral arterial disease.
• Other classification systems, such as the Fontaine classification, may also be used in different clinical settings.
• Healthcare professionals, including vascular specialists, will evaluate the patient’s symptoms, clinical presentation, and imaging findings to determine the appropriate classification and treatment plan for each individual.

Symptoms of Critical Limb Ischemia: The hallmark symptom of CLI is severe pain, usually in the feet or toes, even while at rest. This pain is known as “rest pain” and can be excruciating. The pain occurs because the affected tissues are not receiving enough oxygen and nutrients due to the lack of blood flow. Other symptoms may include:

1. Non-healing Wounds: Ulcers or sores on the legs or feet that do not heal or take an extended time to heal.
2. Gangrene: Tissue death (gangrene) that may appear as black or darkened areas on the toes, feet, or legs.
3. Cool Skin: The skin on the affected limb may feel cool to the touch.
4. Hair and Nail Changes: Decreased hair growth and slow nail growth on the affected limb.
5. Weak or Absent Pulses: The pulses in the affected limb may be weak or absent.
6. Pale Skin Color: The skin on the limb may appear pale or bluish.

It’s crucial to seek immediate medical attention if you experience symptoms of critical limb ischemia, as the condition can progress rapidly and lead to severe complications, including tissue loss and the risk of limb amputation. Early diagnosis and intervention are essential to prevent further damage and improve outcomes.

Treatment of Critical Limb Ischemia: The treatment of CLI aims to restore blood flow to the affected limb and alleviate symptoms. Depending on the severity and extent of the disease, treatment options may include:

1. Medications: Medications may be prescribed to manage risk factors like high blood pressure, cholesterol, and diabetes, which can contribute to the progression of CLI.
2. Angioplasty and Stenting: These procedures involve using a balloon-like device to open up narrowed or blocked arteries and placing a stent to keep the artery open.
3. Bypass Surgery: In more severe cases, bypass surgery may be performed to redirect blood flow around the blocked artery.
4. Endovascular Revascularization: This minimally invasive procedure uses various techniques and devices to improve blood flow.
5. Amputation: In some cases where limb tissue is severely damaged or infected, amputation may be necessary to prevent life-threatening complications.

The choice of treatment depends on various factors, including the location and extent of arterial blockages, the overall health of the patient, and the presence of other medical conditions. Timely intervention and ongoing management are critical to improving outcomes and preserving limb function in individuals with critical limb ischemia.

Summary

• The Rutherford-Becker Classification System, also known as the Rutherford Classification or the Rutherford System, is a classification system commonly used to assess the severity of peripheral arterial disease (PAD) in the lower extremities. It helps in determining the appropriate treatment approach based on the level of arterial occlusion and the resulting clinical presentation. The classification system takes into account both the anatomical and clinical aspects of PAD.
• Here is an overview of the Rutherford-Becker Classification System:

Category 0: Asymptomatic

• No symptoms of PAD are present.

Category 1: Mild claudication

• Mild discomfort or pain in the leg(s) during physical activity, typically relieved by rest.

Category 2: Moderate claudication

• Moderate pain or discomfort in the leg(s) during physical activity, limiting the individual’s ability to walk longer distances.

Category 3: Severe claudication

• Severe pain or discomfort in the leg(s) even at rest, significantly limiting the individual’s ability to walk or engage in physical activity.

Category 4: Ischemic rest pain

• Constant pain or discomfort in the leg(s) even at rest, indicating reduced blood flow and inadequate tissue perfusion.

Category 5: Minor tissue loss

• Superficial ulcers or non-healing wounds on the toes or foot, usually associated with poor blood circulation.

Category 6: Major tissue loss

• Deep ulcers, gangrene, or extensive tissue loss involving the toes, foot, or lower leg, often requiring amputation.

Sources

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC4232437/    
2. https://www1.racgp.org.au/ajgp/2020/may/peripheral-artery-disease-in-lower-limbs
3. https://professional.heart.org/en/-/media/PHD-Files-2/Science-News/2/2024/2024-PAD-guideline-slide-set.pdf?sc_lang=en
4. https://esvs.org/wp-content/uploads/2024/01/PAD-2024-Guidelines.pdf 
5. Lee RE, Patel A, Soon SXY, Chan SL, Yap CJQ, Chandramohan S, Tay LHT, Chong TT, Tang TY. One year clinical outcomes of Rutherford 6 chronic limb threatening ischemia patients undergoing lower limb endovascular revascularisation from Singapore. CVIR Endovasc. 2022 Jul 6;5(1):32. doi: 10.1186/s42155-022-00306-1. PMID: 35792985; PMCID: PMC9259774.https://pmc.ncbi.nlm.nih.gov/articles/PMC9259774/