Validation of the Short Musculoskeletal Function Assessment in patients with battlefield-related extremity vascular injuries

Objective: Vascular extremity injuries can be a significant burden on a patient's long-term quality of life. Currently, no limb-specific surveys have been used to quantify the relation between injury pattern and the resultant physical or psychological impact. The objective of this study was to validate the use of the Short Musculoskeletal Function Assessment (SMFA) in the setting of extremity vascular injury. Methods: The Joint Theater Trauma Registry was queried and filtered for U.S. troops with an extremity vascular injury isolated to a single limb. Injury and management data were obtained, and the SMFA was administered after patient contact and consent. Validity was analyzed by characterization of SMFA score distribution, correlation with 36-Item Short Form Health Survey (SF-36) scores, and assessment of its discriminative capability to external measures of injury severity (ie, Injury Severity Score [ISS], Mangled Extremity Severity Score [MESS], and Medicare Part A disability qualification). Results: At mean follow-up of 5 years, 164 patients (median age, 25 years; interquartile range, 22-31 years) completed both surveys. The overall SMFA Dysfunction Index was 24.8 +/- 15.2 (range, 0-78; skewness, 0.60; floor/ceiling effect, 0%-1.2%; and nonresponse, 0%), and the overall Bother Index was 29.4 +/- 20.2 (range, 0-96; skewness, 0.58; floor/ceiling effect, 0%-4.3%; and nonresponse, 0.6%). SF-36 physical component summary scores correlated inversely with the Dysfunction Index (r = -0.64; P < .01), whereas mental component summary scores correlated inversely with the Bother Index (r = -0.59; P < .01). No difference was found in reported scores between those considered severely injured (ISS > 15) and those not severely injured (ISS <= 15). However, those with mangled extremities (MESS >= 7) reported higher Dysfunction and Bother indices than those with lower scores (P < .05). In addition, patients considered disabled (per Medicare Part A qualifications) reported higher Dysfunction and Bother indices compared with those not considered disabled (P < .05). Conclusions: Use of the SMFA is validated in those with extremity vascular injuries, and it should be considered an adjunctive tool in evaluating long-term patient outcomes.