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PubMed This is a summary of 14 peer-reviewed journal articles Updated
Vascular Surgery

Advanced Risk Stratification: The WIfI System

At a Glance

The WIfI system (Wound, Ischemia, foot Infection) is a grading tool used by doctors to evaluate diabetic foot problems. It scores wound severity, blood flow, and infection levels to determine your clinical stage and guide precise treatments to prevent amputation.

In the past, doctors often focused solely on blood flow when deciding how to treat diabetic foot problems. Today, specialized vascular teams use a more comprehensive and powerful tool called the WIfI system. Developed by the Society for Vascular Surgery, WIfI acts like a “GPS” to map out your risk of amputation and determine exactly which treatments you need [1][2].

Breaking Down the WIfI Score

The name WIfI is an acronym for the three factors that most accurately predict whether a limb can be saved [3]:

  • W – Wound (0 to 3): This score grades the size and depth of any ulcers or the presence of gangrene (dead tissue). A score of 0 means no wound, while a 3 indicates a deep, extensive ulcer or gangrene [4][5].
  • I – Ischemia (0 to 3): This measures how much blood is reaching your foot. Doctors use tests like the Toe-Brachial Index (TBI) to determine if your “pipes” are open enough to heal a wound. A score of 3 means blood flow is severely restricted [6][7].
  • fI – foot Infection (0 to 3): This assesses the severity of any infection, from a simple skin redness (score of 1) to a severe, life-threatening infection that affects your whole body (score of 3) [8][6].

Understanding Your Stage

By combining these three scores, your doctor assigns you a Clinical Stage from 1 to 4 [1]. Knowing your stage is empowering because it directly translates to your level of risk:

  • Stage 1 (Very Low Risk): You have a high chance of healing with standard wound care and do not likely need surgery to improve blood flow [9].
  • Stage 2 (Low Risk): There is a small threat to the limb; your team will monitor you closely to ensure the wound is healing.
  • Stage 3 (Moderate Risk): The threat is significant. You likely need aggressive treatment, such as antibiotics or a procedure to restore blood flow [10].
  • Stage 4 (High Risk): There is a high risk of major amputation within one year if aggressive action isn’t taken immediately [11][9].

Why WIfI is the Modern Standard

Before WIfI, older systems (like the Rutherford or Fontaine scales) only looked at symptoms like leg pain. WIfI is superior because it recognizes that a patient can have “decent” blood flow but still be at high risk because of a deep infection or a very large wound [12][13].

Using this system allows your multidisciplinary team to move quickly. For example, if your “Ischemia” score is a 3, your surgeon knows that the wound will likely never heal until blood flow is restored through revascularization [14]. If your “Infection” score is rising, your team knows to shift the focus to aggressive antibiotics and surgical cleaning (debridement) [6]. By following the WIfI “map,” your care becomes precise, personalized, and proactive.

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Common questions in this guide

What does the WIfI score stand for?
WIfI stands for Wound, Ischemia (lack of blood flow), and foot Infection. Doctors score each of these three factors from 0 to 3 to map out your overall risk of amputation and determine the most effective treatment plan for your foot.
How do doctors measure ischemia for the WIfI score?
Doctors evaluate ischemia by testing how much blood is reaching your foot. They often use non-invasive tests like the Toe-Brachial Index (TBI) to determine if your blood vessels are open enough to deliver the oxygen and nutrients needed to heal a wound.
What does a WIfI Clinical Stage 4 mean?
A Stage 4 score indicates a high risk for a major amputation within one year if aggressive action isn't taken. Your care team will likely recommend immediate interventions, such as a revascularization procedure to restore blood flow or surgery to clear out severe infection.
Why is the WIfI system better than older grading scales?
Unlike older systems that primarily focused on symptoms like leg pain, WIfI evaluates wound size, blood flow, and infection severity together. This comprehensive approach recognizes that a patient with decent blood flow can still be at high risk due to a deep infection.
Will my WIfI score change during treatment?
Yes, your multidisciplinary team will regularly re-stage your score to monitor your progress. As treatments like antibiotics clear up an infection or a procedure improves your blood flow, your clinical stage should improve, lowering your overall amputation risk.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my most recent exam, what are my individual scores for Wound (0-3), Ischemia (0-3), and Infection (0-3)?
  2. 2.What is my overall WIfI Clinical Stage (1, 2, 3, or 4)?
  3. 3.Does my WIfI Stage suggest a high risk for major amputation in the next 12 months, and how does our current treatment plan lower that risk?
  4. 4.If my Ischemia score is a 2 or 3, should we be scheduling a revascularization procedure immediately to help this wound heal?
  5. 5.How often will you be 're-staging' me to see if my WIfI scores are improving with treatment?

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References

References (14)
  1. 1

    A Review of WIfI Clinical Staging to Predict Outcomes in Patients With Threatened Limbs.

    Cook IO, Mayor JM, Mills JL

    Annals of vascular surgery 2024; (107()):146-153 doi:10.1016/j.avsg.2024.01.024.

    PMID: 38583759
  2. 2

    WIfI classification: the Society for Vascular Surgery lower extremity threatened limb classification system, a literature review.

    Cerqueira LO, Duarte EG, Barros ALS, et al.

    Jornal vascular brasileiro 2020; (19()):e20190070 doi:10.1590/1677-5449.190070.

    PMID: 34178056
  3. 3

    The application of the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification to stratify amputation risk.

    Mills JL

    Journal of vascular surgery 2017; (65(3)):591-593 doi:10.1016/j.jvs.2016.12.090.

    PMID: 28236912
  4. 4

    Duration from Wound Occurrence to Referral to a Vascular Center in Japanese Patients with Critical Limb Ischemia.

    Takahara M, Iida O, Soga Y, et al.

    Annals of vascular diseases 2020; (13(1)):56-62 doi:10.3400/avd.oa.19-00102.

    PMID: 32273923
  5. 5

    Outcomes and Predictors of Wound Healing among Patients with Complex Diabetic Foot Wounds Treated with a Dermal Regeneration Template (Integra).

    Hicks CW, Zhang GQ, Canner JK, et al.

    Plastic and reconstructive surgery 2020; (146(4)):893-902 doi:10.1097/PRS.0000000000007166.

    PMID: 32639434
  6. 6

    SVS WIfI score as a predictor of amputation after onset of CLI: Validation in an Irish tertiary vascular unit.

    Ahmed Z, Raza MZ, Worrall AP, et al.

    The surgeon : journal of the Royal Colleges of Surgeons of Edinburgh and Ireland 2023; (21(1)):48-53 doi:10.1016/j.surge.2022.02.005.

    PMID: 35337751
  7. 7

    Clinical characteristics of patients with diabetic foot using WIfI classification-A pilot study in Vietnam.

    Bao HLT, Thuy NH

    Endocrinologia, diabetes y nutricion 2023; (70(8)):540-547 doi:10.1016/j.endien.2023.10.003.

    PMID: 38783728
  8. 8

    Acute diabetic foot disease.

    Jones A, Hinchliffe R

    The British journal of surgery 2024; (111(9)) doi:10.1093/bjs/znae226.

    PMID: 39316572
  9. 9

    Real-world application of Wound, Ischemia, and foot Infection scores in peripheral arterial disease patients.

    Smith ME, Braet DJ, Albright J, et al.

    Journal of vascular surgery 2024; (80(4)):1216-1223 doi:10.1016/j.jvs.2024.04.071.

    PMID: 38723913
  10. 10

    Validation of the WIfI classification in the Vascular Quality Initiative database.

    Alameddine D, Satam K, Slade MD, et al.

    Journal of vascular surgery 2025; (82(2)):549-558.e2 doi:10.1016/j.jvs.2025.03.001.

    PMID: 40056961
  11. 11

    Validation of Wound, Ischemia, and Foot Infection Classification in Infrapopliteal Arterial Disease Undergoing Endovascular Therapy.

    Guo J, Guo J, Gao X, et al.

    JACC. Cardiovascular interventions 2026; (19(8)):1004-1017 doi:10.1016/j.jcin.2026.01.311.

    PMID: 42055647
  12. 12

    Risk Stratification for 2-Year Mortality in Patients with Chronic Limb-Threatening Ischemia Undergoing Endovascular Therapy.

    Hata Y, Iida O, Asai M, et al.

    Journal of atherosclerosis and thrombosis 2021; (28(5)):477-482 doi:10.5551/jat.57711.

    PMID: 32713933
  13. 13

    The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system predicts wound healing better than direct angiosome perfusion in diabetic foot wounds.

    Weaver ML, Hicks CW, Canner JK, et al.

    Journal of vascular surgery 2018; (68(5)):1473-1481 doi:10.1016/j.jvs.2018.01.060.

    PMID: 29803684
  14. 14

    Outcomes of Critical Limb Ischemia in an Urban, Safety Net Hospital Population with High WIfI Amputation Scores.

    Ward R, Dunn J, Clavijo L, et al.

    Annals of vascular surgery 2017; (38()):84-89 doi:10.1016/j.avsg.2016.08.005.

    PMID: 27546850

This page explains the WIfI scoring system for educational purposes only. Your vascular team or podiatrist is the best source for interpreting your specific WIfI clinical stage and determining your personalized treatment plan.

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