Association between trochanteric fractures and gluteal muscle size, density in older women: a cross-sectional study at a university hospital

PURPOSE: This study aimed to investigate differences in hip muscle area and density between older women with femoral neck fractures (FNF) and trochanteric fractures (TRF). DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: The study was conducted at a university hospital. A total of 554 older women patients were enrolled, comprising 314 with FNF (mean age 77.02±7.15 years) and 240 with TRF (mean age 79.70±6.91 years), for comparative analysis. METHODS: CT scans were used to measure the area and density of the gluteus medius and minimus muscles (G.Med/MinM) and the gluteus maximus muscle (G.MaxM). Areal bone mineral density (aBMD) of the total hip (TH) and femoral neck (FNaBMD) were quantified using quantitative CT. The cohort was stratified by age (cut-off 80 years) to explore age-specific associations. RESULTS: Among all subjects, the FNF group exhibited significantly higher muscle parameters compared with the TRF group (p<0.001). With adjustments made for age, body mass index (BMI) and THaBMD, all muscle parameters, except G.Med/MinM density, showed significant correlations with TRF. In the age ≥80 group, no statistically significant correlations were observed between hip muscle parameters and TRF. Conversely, in the age <80 group, adjusting for age, BMI and THaBMD revealed significant associations between decreased muscle density and area of both G.MaxM and G.Med/MinM with TRF. CONCLUSIONS: Our findings suggest that in older women, particularly those under 80 years of age, gluteus muscle parameters are associated with TRFs, independently of BMD.