SLR - November 2018 - James D. Barksdale

The Mangled Extremity Score and Amputation: Time for a Revision

Reference: Loja MN, Sammann A, DuBose J, Li CS, Liu Y, Savage S, Scalea T, Holcomb JB, Rasmussen TE, Knudson MM; AAST PROOVIT Study Group. The Mangled Extremity Score and Amputation: Time for a Revision. J Trauma Acute Care Surg. 2017 Mar;82(3):518–523.

Scientific Literature Review

Reviewed By: James D. Barksdale, DPM
Residency Program: New York Presbyterian/Queens, Flushing, NY

Podiatric Relevance: The Mangled Extremity Severity Score (MESS) was developed in 1990 to attempt to predict the need for amputation following a traumatic event to an extremity. The original scoring system included consideration of the degree of skeletal and soft-tissue injury, limb ischemia, presence of shock, age and ischemia time. This study sought to apply the MESS to a data set prospectively in modern times and hypothesized that the MESS would not be a reliable indicator for the necessity of amputation.

Methods: A prospective, prognostic Level III study was performed in which the MESS was applied to patient data collected in the American Association for the Surgery of Trauma PROspective Vascular Injury Treatment registry. This registry contains prospectively collected demographic, diagnostic, treatment and outcome data collected from 14 Level I trauma centers across the United States. For the purposes of this study, data was gathered from February 2013 to August 2015. Of note, the database does not distinguish the severity of vein, nerve or orthopaedic injury but simply reports a binary value of “injured” or “not injured.” Univariable regression was used to look at the correlation of the MESS, as well as each MESS component with the odds of amputation. The probability of amputation was modeled using univariable logistic regression to predict amputations with a MESS cutoff of 5 and 8. Finally, demographics of patients with the MESS cutoff of 8 were compared using Wilcoxon rank-sum test and Fisher exact test.

Results: Between 2013 and 2015, 230 patients with lower-extremity arterial injuries were entered into the PROspective Vascular Injury Treatment registry. A MESS of 8 or greater was associated with a longer stay in the hospital and intensive care. Of the patients' limbs, 81.3 percent were ultimately salvaged, and 18.7 percent required primary or secondary amputation. However, after controlling for confounding variables, including mechanism of injury, degree of arterial injury, injury severity score, arterial location and concomitant injuries, the MESS between salvaged and amputated limbs was no longer significantly different. Importantly, a MESS of 8 predicted in-hospital amputation in only 43.2 percent of patients.

Conclusions: This study highlights the critical need to utilize a team-oriented approach when dealing with acute traumatic injuries to the extremities. This study takes into account confounding variables that are not included in the original MESS score. These variables highlight the fact that an initially elevated MESS score does not necessarily predict the need for in-hospital amputation, and many patients may go on to successful salvage after traumatic events. There are limitations to this study as there is no long-term data with regard to functional outcome and quality of life, although it shows that using MESS alone is not a reliable or predictable indicator of amputation following a traumatic event. 

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