Diabetic Foot Ulcer Classification Systems

Diabetic Foot Ulcer
Diabetic Foot Ulcer – Wagner Grade 2

It is crucial to apply a standardized measurement system to evaluate whether a diabetic foot ulcer is responding to care, as a result several classification systems have been proposed.

At the present time no specific system has been universally accepted.  Even so, most clinicians use one of the available systems when assessing and documenting a diabetic ulcer.

In this article we will discuss two commonly used classification systems;  The Wagner diabetic foot ulcer grade classification system and the University of Texas diabetic foot ulcer classification system.

The Wagner Diabetic Foot Ulcer Grade Classification System

The Wagner diabetic foot ulcer classification system assesses ulcer depth and the presence of osteomyelitis or gangrene by using the following grades:

  • Grade 0 – intact Skin
  • Grade 1 – superficial ulcer of skin or subcutaneous tissue
  • Grade 2 – ulcers extend into tendon, bone, or capsule
  • Grade 3 – deep ulcer with osteomyelitis, or abscess
  • Grade 4 – partial foot gangrene
  • Grade 5 – whole foot gangrene

Note:  While the wound shown in the above image may appear to be a grade 3 ulcer, upon assessment no abscess or osteomyelitis was found.  Beneath the superficial necrotic tissue was exposed tendon.

The University of Texas Diabetic Foot Ulcer Classification System

The University of Texas system grades diabetic foot ulcers by depth and then stages them by the presence or absence of infection and ischemia:

  • Grade 0 – pre-or postulcerative site that has healed
  • Grade 1 – superficial wound not involving tendon, capsule, or bone
  • Grade 2 – wound penetrating to tendon or capsule
  • Grade 3 – wound penetrating bone or joint

Within each wound grade there are four stages:

  • Stage A – clean wounds
  • Stage B – non-ischemic infected wounds
  • Stage C – ischemic noninfected wounds
  • Stage D – ischemic infected wounds

Additional Diabetic Foot Ulcer Classification Systems

The following chart from Wounds International highlights additional classifications systems.

diabetic foot ulcer classification systems
Source: wounds international.com

For detailed information on the above chart refer to “Best Practice Guidelines:  Wound Management in Diabetic Foot ulcers”


While each system uses a different approach to classify a wound,  similarly each system classifies the wound according to depth, presence of ischemia, and presence of infection.

Regardless of which classification system is used, it is essential that the system be used consistently across the healthcare team and be recorded appropriately in the patient’s records.

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  1. Thank you for the information on Diabetic foot ulcer classification systems. I had no idea that diabetic foot ulcers could get so bad they reach tendons or even the bone. I wonder how you catch an ulcer early, or how to treat one that’s gone so deep it affects a tendon or bone.

  2. A diabetic has a heel ulcer completely covered by eschar. Should this be “Staged” or “Graded” according to the Wagner Grading Scale. If “Graded”, what would be the Grade ?

      1. Hi Matthew, That is a difficult question one that many professionals struggle will. The cause of the ulcer is clearly related to both disease processes and both pressure and diabetes will need to be addressed. For documentation purposes, the PRIMARY cause of the ulcer would be documented. If the ulcer was caused by pressure and is completely covered by eschar, it would be documented as an unstageable pressure ulcer with the comorbidity of diabetes. For more infomation refer to the following article: http://www.diabeticfootcanadajournal.ca/download/content/4588

  3. Thank you for that. Once the eschar is removed and is visualuzed, would the classification ever be converted to a Wagner Grade or does it remain “Staged” ?

  4. Thank you so much. This topic at our wound center seems to raise more questions the more we talk about it. If we derermine that a diabetic foot ulcer should be graded and is completely covered by eschar, what Wagner Grade would it be ? Thanks

  5. Can a Wagner classification be given to an infected below knee amputation residual limb or does it have to be a foot?

    1. Hi Alex! Thanks for your inquiry. A Wagner grade 1 is considered a superficial ulcer, not a full thickness wound.

      1. Thank you for the answer! I do have a followup question. If you have a diabetic wound that extends into the subcutaneous layers, lets say 2cm, but does not reach tendon, bone, or joint would that be considered a Wagner grade 1 or grade 2?

  6. Is anybody aware of any licensing for the Wagner Diabetic Foot Ulcer Grade Classification System?

  7. Are non-pressure ulcers “reverse-graded” as they heal – or are they reported at their deepest like pressure ulcers?

  8. i am doing research on diabetic foot ulcers dressings.I want to compare between papya dressing and povidone 10 % dressing.i need a criteria to declare diabetioc foot ulcer is healed .which is practical and can be documented .
    Dr amir rasool
    [email protected]

  9. Can a Wagner DFU ever be “back-staged ” e.g. from a Grade 2 to a grade 1 or stage C to stage A – once improved?

  10. As a diabetic ulcer heals, will the Grade for that wound improve? Or is it like a pressure ulcer and the stage never changes after it is staged?

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