| Grade: 0 |
| Ulcer |
| No ulcer |
| Gangrene |
| No gangrene |
| Clinical description |
| Ischemic rest pain (requires typical symptoms + ischemia grade 3); no wound |
| Grade: 1 |
| Ulcer |
| Small, shallow ulcer(s) on distal leg or foot; no exposed bone, unless limited to distal phalanx |
| Gangrene |
| No gangrene |
| Clinical description |
| Minor tissue loss. Salvageable with simple digital amputation (1 or 2 digits) or skin coverage |
| Grade: 2 |
| Ulcer |
| Deeper ulcer with exposed bone, joint or tendon; generally not involving the heel; shallow heel ulcer, without calcaneal involvement |
| Gangrene |
| Gangrenous changes limited to digits |
| Clinical description |
| Major tissue loss salvageable with multiple (≥3) digital amputations or standard TMA ± skin coverage. |
| Grade: 3 |
| Ulcer |
| Extensive, deep ulcer involving forefoot and/or midfoot; deep, full thickness heel ulcer ± calcaneal involvement |
| Gangrene |
| Extensive gangrene involving forefoot and/or midfoot; full thickness heel necrosis ± calcaneal involvement |
| Clinical description |
| Extensive tissue loss salvageable only with a complex foot reconstruction or nontraditional TMA (Chopart or Lisfranc); flap coverage or complex wound management needed for large soft tissue defect. |
TMA, Transmetatarsal amputation.