Determination of a Low Skeletal Muscle Mass Index Using the Mass of the Gluteus Medius in Older Patients With Hip Fractures.

This study evaluated the relationship between the muscle mass of the gluteus medius (GM) and skeletal muscle mass index (SMI) measured in patients with hip fractures. In this study, 141 patients with hip fractures were divided into those with high or low SMI. The GM index (GMI) was calculated by dividing the GM by the square of the height in meters. The correlation between GMI and SMI was subsequently analyzed, and cutoff values for determining the loss of skeletal muscle mass were calculated using the receiver operating characteristic curve. GMI and SMI showed a positive correlation for both sexes (male: r = .890, female: r = .626, p < .001). The GMI cutoff values were 19.460 cm2/m2 for males and 17.850 cm2/m2 for females. Skeletal muscle mass evaluation of the GM could contribute to hip fracture recovery by improving mobility and facilitating the early diagnosis of loss of SMM.