Psoas Muscle Volume as an Opportunistic Diagnostic Tool to Assess Sarcopenia in Patients with Hip Fractures: A Retrospective Cohort Study

Purpose: This study aims to determine whether the psoas volume measured from a pelvic computed tomography (CT) could be a potential opportunistic diagnostic tool to measure muscle mass and sarcopenia in patients with hip fractures. Methods: This was a retrospective cohort study. In total; 57 consecutive patients diagnosed with hip fractures who underwent surgery were enrolled. A cross-sectional area of the psoas muscle was measured at the lumbar (L) 3 and L4 vertebrae from a pelvic CT for the diagnosis of hip fractures. The psoas muscle volume was calculated with a three-dimensional modeling software program. The appendicular skeletal muscle mass (ASM) and preoperative handgrip strength (HS) were measured. The correlations between the psoas muscle volume/area and ASM/HS were assessed. Data on patient demographics; postoperative complication; length of hospital stay; and Koval scores were also recorded and analyzed with respect to the psoas muscle area/volume. Results: The psoas muscle volume and adjusted values were significantly correlated with ASM; which showed a stronger correlation than the psoas muscle area did at the L3 or L4 level. HS was correlated with the psoas volume or adjusted values; but not with the cross-sectional area of the psoas muscle. Among the adjusted values; the psoas muscle volume adjusted for the patient’s height (m(2)) showed a strongest correlation with ASM and HS. The psoas muscle volume was not significantly correlated with postoperative complications or short-term functional outcomes. Conclusions: The psoas muscle volume measured from a pelvic CT for the diagnosis of hip fractures showed a stronger correlation with ASM and HS than the cross-sectional area did. Therefore; the psoas muscle volume could be a potential diagnostic tool to assess the quantity of the skeletal muscle in patients with hip fractures without an additional examination.