Mangled Extremity Severity Score (MESS)
Mangled Extremity Severity Score (Johansen 1990): the amputation-risk score from skeletal/soft-tissue injury, limb ischemia, shock, and age (ischemia doubled > 6 h).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Skeletal/soft-tissue injury energy
- 3
- Limb ischemia grade
- 2
- Ischemia time > 6 hours
- Yes
- Shock grade
- 0
- Age grade
- 0
Result: MESS 7 (ischemia subscore doubled for ischemia time > 6 h): at or above the threshold of 7 historically associated with amputation.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Threshold
- a total >= 7 was historically associated with amputation; the score informs, never dictates, the salvage-vs-amputation decision.
What you enter
- Skeletal/soft-tissue injury energy (1-4)
- Limb ischemia grade (1-3)
- Ischemia time > 6 hours (doubles the subscore)
- Shock grade (0-2)
- Age grade (0-2)
How this is calculated
- Components
- skeletal/soft-tissue energy 1-4; limb ischemia 1-3, DOUBLED if ischemia time > 6 h; shock 0-2 by systolic BP; age band 0-2.
Johansen K, Daines M, Howey T, Helfet D, Hansen ST Jr. Objective criteria accurately predict amputation following lower extremity trauma. J Trauma. 1990;30(5):568-573. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.