Computed tomographic measurements of the psoas muscle as a predictor of mortality in hip fracture patients: Muscle attenuation helps predict mortality in hip fracture patients

Introduction In recent years, sarcopenia has been identified as an important risk factor of patient prognosis. The aim of this study was to determine the association between prognosis of hip fracture and sarcopenia and to evaluate the prognostic performance of psoas muscle volume and attenuation measurements in hip computed tomography (CT). Material and methods This was a retrospective cohort study of patients with hip fracture in our institution from 2014 to 2017. Baseline character data and hip CT scans were obtained. Two readers independently measured muscle size (cross-sectional area) and attenuation of the psoas muscle at the L4 vertebra on CT scans. Logistic regression analysis was used to identify the association between mortality and muscle index (the sum of the left and right muscle sizes divided by patient height) and muscle attenuation after adjusting for demographic variables. In addition, receiver operating characteristic (ROC) curves were obtained. Results In the 462 patients included in the study, in-hospital mortality was 4%. Multivariate logistic regression analysis revealed that muscle attenuation was a risk factor for mortality. Among baseline characteristics, age, sex, diastolic blood pressure, and albumin were significant variables for mortality. The area under the ROC curve (AUC) of muscle attenuation for prediction of death was 0.839 (0.803–0.872) with 84.2% sensitivity and 69.5% specificity. Furthermore, when we combined all independent factors according to the results, the AUC was 0.929 (0.902–0.951) with 84.2% sensitivity and 93.6% specificity for prediction of mortality among hip fracture patients. Conclusion Among many variables, the most significant was muscle attenuation. CT is the most typical modality to determine treatment of hip fracture patients. Measuring muscle size and attenuation is simple using PACS software. Muscle attenuation has significant value for predicting the prognosis of hip patients.