Mangled Extremity Severity Score (MESS Score)
The Mangled Extremity Severity Score can be applied to all adult patients who present with extremity trauma, particularly lower extremity trauma.
The Mangled Extremity Severity Score (MESS) was developed to discriminate between salvageable and doomed limbs in the setting of lower extremity trauma.
- MESS could provide an early prognosis on the injured limb at time of Emergency Department or initial contact with healthcare system.
- Newer surgical techniques since the development of the score in the late 1980s may alter the outcome of patients with a MESS ≥7.
- Has been validated for upper extremity injuries as well. however as the MESS creator Dr. Johansen suggests, upper extremities are profoundly more important than lower extremities and prosthesis much more primitive, so nearly every effort at salvage should be attempted.
- Only large, prospective, multi-center study of the MESS found that a cut-off of 7 had poor sensitivity and mediocre specificity.
- MESS Creator Dr. Johansen suggests that, due to newer techniques that increase the probability of limb salvage, a higher MESS “cut off” may be considered, perhaps 8 or 9.
- The MESS can potentially identify at time of initial evaluation patients who are candidates for successful limb salvage vs future amputation.
- The MESS utilizes variables that can be readily obtained without extensive and complicated measurements or calculations.
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- All patients with significant trauma require a thorough trauma assessment and resuscitation.
- Trauma victims require management of significant craniocerebral, thoracic, abdominal, and pelvic injuries prior to consideration of limb salvage.
After initial stabilization and resuscitation in the Emergency Department, urgent orthopedics consultation or transfer to a higher level of care is critical as time of ischemia plays a significant role in the MESS.
Patients with a MESS ≥ 7 are likely to require amputation secondary to their limb trauma.
Addition of the assigned points; if there has been limb ischemia for more than 6 hours, the "limb ischemia" points are doubled.
Facts & Figures
|Limb Ischemia*||Reduced Pulse but Normal Perfusion||+1|
|Pulseless, Paresthesias, Slow Capillary Refill||+2|
|Cool, Paralysis, Numb/Insensate||+3|
|Patient Age Range||< 30||0|
|Shock||SBP > 90 mmHg Consistently||0|
|Injury Mechanism||Low Energy (stab, gunshot, simple fracture)||+1|
|Medium Energy (dislocation, open/multiple fractures)||+2|
|High Energy (high speed MVA or rifle shot)||+3|
|Very High Energy (high speed trauma with gross contamination)||+4|
*If Limb Ischemia present > 6 hours, Limb Ischemia Points are multiplied by 2
- Published in 1990 based on a retrospective chart review of over 250 lower extremity long bone fractures at Harborview Medical Center in Seattle.
- Authors derived four clinical variables as the basis for the Mangled Extremity Severity Score (MESS): skeletal/soft-tissue injury, limb ischemia and time, shock, and age.
- Prospectively applied MESS at two different hospitals consisting of two separate patient populations on opposite sides of the country.
- Found that all salvaged limbs had a MESS ≤ 6 while all amputated limbs had a MESS > 6.
- Patients with failed limb salvage requiring delayed amputation had a significantly increased duration of hospitalization, required more operative procedures, increased hospital costs, and had higher morbidity and mortality.
- Though their study found that a MESS ≥7 was 100% predictive for amputation, they cautioned that their sample size was small.
Subsequently validated in a retrospective study of 24 patients with lower extremity injuries that once again showed that a MESS ≥7 was 100% predictive of amputation.
- Study did have patients with a MESS ≤ 6 who still needed amputation, in contrast to the original derivation study where no patient in that group required amputation.
A large, multi-center, prospective study comparing the utility of several lower extremity injury-severity scores, including MESS was published in 2001.
- Using a MESS cut-off of 7, the authors looked at outcomes of 556 limbs in 539 patients.
- In contrast to the original study, they excluded limbs that were amputated within 24 hours as they felt the limb-salvage score would be of little utility in these patients.
- 493 limbs in 477 patients were followed for limb salvage at 6 months.
- Authors found that a MESS cut-off of 7 was only 46% sensitive and 91% specific for predicting amputation.
MESS and the Upper Extremity
- A retrospective 1994 study of 37 patients with 43 upper extremity injuries replicated the original MESS study, finding all 9 injuries with MESS ≥7 were amputated while the remaining 34 with MESS < 7 were salvaged.
- More recent case series from 2005 reported two cases with MESS scores of 11 and 7, both of which were salvaged successfully.
Original/Primary ReferenceJohansen, K, et. al. Objective criteria accurately predict amputation following lower extremity trauma. Journal of Trauma, 1990
From the Creator
- Why did you develop the Mangled Extremity Severity Score? Was there a clinical experience that inspired you to create this tool for clinicians?
- Johansen: In the 1980s, while I was Chief of Vascular Surgery at Harborview Medical Center, the Level I trauma center here in Seattle, several trauma victims with severely damaged lower extremities died after vain (and, in retrospect, misguided) attempts at limb salvage. This experience reflected recent observations from other trauma centers (e.g. Bondurant et al from Houston), and led to a retrospective analysis of such patients to discern whether objective clinical and demographic data available early in such patients' course might predict the likelihood of success vs. failure in limb salvage efforts. A subsequent prospective trial, carried out at Harborview and at Tampa General Hospital in Florida, came to the same conclusion -- that grading soft tissue/skeletal injury, ischemia, presence of shock and patient age (a surrogate for medical comorbidities) seemed to predict limb salvage success/failure at a score of 7.
- What pearls, pitfalls and/or tips do you have for users of the Mangled Extremity Severity Score? Are there cases when it has been applied, interpreted, or used inappropriately?
- I do not believe MESS should be considered dependable, and therefore utilized for decision-making, in kids, in upper extremity trauma or to predict longterm functional outcomes. This is even though a number of publications have suggested the validity of MESS in each of these three areas (an example, I believe, of the phenomenon of "true - true - unrelated"!)
- What influence do you think more recent advances in surgical techniques and technology have had on the performance of the MESS? Do you think the traditional cut-off of 7 for limb viability should be adjusted as a result?
- This is a very important question. In fact, given the advent of improved imaging modalities, minimally-invasive revascularization techniques, the WoundVac concept, sophisticated free tissue transfer options, Ilizarov methods for limb-length discrepancy etc., I think MESS as we presented it in 1990 is obsolete and needs to be updated. The appropriate contemporary lower extremity threshold value (we avoid the term "cut-off"!!) may be up to 8 or even 9. We indicated this precise point -- that MESS was a "snapshot in time" which needed to be modified serially as new limb salvage techniques became available -- when we initially presented this scoring system. An editorial emphasizing this view, to be submitted to the Journal of Trauma, is in preparation.
- Your score has also been validated in upper extremity. In your opinion, should a different cut off be used in the upper extremity?
- Upper extremities are profoundly more important functionally than lower extremities are; upper extremity prostheses are much more primitive and less functional than lower extremity prostheses. Accordingly, in view of the fact that even a numb, insensate, immobile upper extremity may be of more use to the trauma victim than even the best upper extremity prosthesis, every effort should be made to salvage badly damaged upper extremities rather than amputating them.
About the Creator
Kaj Johansen, MD, PhD, is board certified in general and vascular surgery and practices at The Polyclinic and Swedish Medical Center. He is also a clinical professor of surgery at the University of Washington School of Medicine. Dr. Johansen provides care across the entire vascular surgical spectrum, with emphasis on thoracic outlet syndrome and gait salvage surgery.
To view Dr. Kaj Johansen's publications, visit PubMed