The Mangled Digit Severity Score: Determining Salvageability of Severe Digital Injuries

Abstract

Purpose

The assessment, prognostication, and decision-making for mangled digital injuries can be challenging, even for experienced surgeons. This study aimed to develop a Mangled Digit Severity Score (MDSS) to predict whether a mangled digit should be salvaged.

Methods

An anonymous questionnaire was sent to 67 hand surgeons at seven hand trauma centers as an initial survey panel. Participants were provided a list of factors influencing outcomes following a mangled digit injury and were asked to assign weights from 0–10 for each factor reflecting its relative importance in determining likelihood of functional salvage versus failure or secondary amputation. Using a modified Delphi method, iterative questionnaire rounds then were performed with seven expert panelists and consensus established. The final ratings were used to develop a weighted scoring system to assess mangled digits. A retrospective single-center review was conducted to validate the scoring system. The sensitivity and specificity for amputation at different MDSS prognostic thresholds were evaluated, and a receiver operating characteristic curve and area under the curve were calculated.

Results

From initial surgeon responses (36/67 response rate) and two subsequent rating rounds, consensus was achieved on 14 factors, including crush/avulsion mechanism, intraarticular fracture, and zone II flexor tendon injury. Final weights for all factors ranged between 3–9. Among 54 mangled digits reviewed, digits that were salvaged had a significantly lower MDSS than those that underwent amputation. The MDSS demonstrated an area under the curve of 0.87. At a threshold of 35, the MDSS achieved a sensitivity of 60% and specificity of 88% in predicting amputation.

Conclusions

The MDSS was developed through a consensus of experts and is a useful tool for identifying mangled digits that may not be salvageable.

Clinical relevance

The MDSS provides a structured framework for the assessment of severely injured digits with a prognostic guideline for amputation or salvage.