A prospective evaluation of the clinical utility of the lower-extremity injury-severity scores

Background: High-energy trauma to the lower extremity presents challenges w ith regard to reconstruction and rehabilitation. Failed efforts at limb sal vage are associated with increased patient mortality and high hospital cost s. Lower-extremity injury-severity scoring systems were developed to assist the surgical team with the initial decision to amputate or salvage a limb. The purpose of the present study was to prospectively evaluate the clinica l utility of five lower-extremity injury-severity scoring systems. Methods: Five hundred and fifty-six high-energy lower-extremity injuries we re prospectively evaluated with use of five injury-severity scoring systems for lower-extremity trauma designed to assist in the decision-making proce ss for the care of patients with such injuries. Four hundred and seven limb s remained in the salvage pathway six months after the injury. The sensitiv ity, specificity, and area under the receiver operating characteristic curv e were calculated for the Mangled Extremity Severity Score (MESS); the Limb Salvage Index (LSI); the Predictive Salvage index (PSI); the Nerve injury Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Sc ore (NISSSA); and the Hannover Fracture Scale-97 (HFS-97) for ischemic and nonischemic limbs. The scores were analyzed in two ways: including and excl uding limbs that required immediate amputation. Results: The analysis did not validate the clinical utility of any of the l ower-extremity injury-severity scores. The high specificity of the scores i n all of the patient subgroups did confirm that low scores could be used to predict limb-salvage potential. The converse, however, was not true. The l ow sensitivity of the indices failed to support the validity of the scores as predictors of amputation. Conclusions: Lower-extremity injury-severity scores at or above the amputat ion threshold should be cautiously used by a surgeon who must decide the fa te of a lower extremity with a high-energy injury.