The role of proximal femoral bone, muscle and subcutaneous adipose tissue in the discriminating of hip fracture types in elderly women.

PURPOSE: We aimed to explore the value of proximal femoral bone, muscle, and mid-thigh subcutaneous adipose tissue (MSAT) parameters in the discriminating of hip fracture (HF) types and to compare the performance of these parameters.

METHODS

661 female patients with acute low-energy HF and 283 female healthy controls (HC) within the Shanghai Sixth People's Hospital were retrospectively analyzed. HF types include femoral neck fracture (FNF) and intertrochanteric fracture (ITF). Quantitative computed tomography (CT) was performed on the non-fractured hip of HFs and HCs to obtain the areal bone mineral density (aBMD) and volume BMD (vBMD). From the CT images, cross-sectional area and attenuation of gluteal muscles, mid-thigh muscles and MSAT were determined. Multiple combined models incorporating bone, muscle, and MSAT parameters were constructed using multivariate logistic regression to differentiate between various types of HFs, and their performance was compared.

RESULTS

The univariate analysis showed that the correlation between most BMD parameters and HF was significantly stronger when compared to the correlation between muscle and MSAT parameters and HF. In the FNF group, the areas under the curve (AUC) of FN BMD parameters were the highest (all AUC > 0.78). In Model 1, multiple parameters, including MSAT, BMD, and BMI, were included. The combination of these parameters resulted in an increased AUC value (AUC = 0.830, 95% CI, 0.791-0.864, P < 0.001). Model 6 stands out among these models (AUC = 0.877, 95% CI, 0.843-0.906, P < 0.001), offering a relatively comprehensive set of parameters. Model 8 demonstrates an exceptional AUC value exceeding 0.9 after combining variables (AUC = 0.919; 95% CI, 0.876-0.951; P < 0.001).

CONCLUSION

Gluteus medius and minimus muscles (G.Med/MinM) area, FN aBMD, FN vBMD and body mass index are all important independent factors in discriminating between different types of HF in women, and BMD plays a more significant role in acute HF compared to the size or density of gluteal muscles.