Re-evaluation of cutting criteria for limb amputation using the Mangled Extremity Severity Score.

Background: Decision-making regarding amputation in severe open extremity fractures is challenging. Various scoring systems, such as the Mangled Extremity Severity Score (MESS), have guided critical decisions for nearly three decades, yet no consensus or clear criteria have been established. The aim of this study is to identify predictive factors for amputation in open extremity fractures using MESS.

Method: We retrospectively analyzed patients with open limb fractures classified as Gustilo-Anderson type 3B or 3C, treated between April 2013 and September 2024 at two tertiary hospitals in Osaka, Japan. We compared MESS values between patients who underwent limb preservation and those who required amputation at any time during hospitalization and performed receiver operating characteristic curve analysis to identify the optimal MESS cut-off value for predicting amputation.

Results: The preservation and amputation groups comprised 36 and 18 patients, respectively. The mean (±SD) total MESS was significantly lower in the preservation group than that in the amputation group (5.7±1.5 vs 8.0±1.4; p≤0.001). MESS ≥7 demonstrated a sensitivity of 83% and a specificity of 78%, whereas MESS ≥8 showed increased specificity (92%) with slightly reduced sensitivity (78%). The area under the curve for MESS was 0.86, and for MESS ≥8, it was significantly higher than that for MESS ≥7 (p=0.020).

Conclusion: Although MESS remains a valuable tool for decision-making in amputation, our findings suggest that a revised cut-off score of 8 may better reflect the current trauma management capabilities. This adjustment could enhance the predictive accuracy of MESS, facilitating more informed clinical decisions in severe limb trauma.

Level of evidence: III.