Discrimination of hip fractures by quantitative ultrasound of the phalanges and the calcaneus and dual X-ray absorptiometry

Abstract 

The aim of the current study was to evaluate the ability of different techniques used for the assessment of bone status to discriminate between postmenopausal women with and without hip fracture. Fifty-one postmenopausal women (mean age 64.5±6.5) who had sustained a low energy hip fracture and 51 age-matched controls (mean age 64.6±6.0) were studied. Quantitative ultrasound (QUS) assessment was carried out using the Ubis 3000 device capable of measuring broadband ultrasound attenuation (BUA) and speed of sound at the calcaneus (SOS_C) and the Sunlight Omnisense device capable of estimating speed of sound at the phalanges (SOS_P). Femoral neck bone mineral density (BMD) was assessed using dual X-ray absorptiometry. Correlations between QUS variables ranged from r=0.35 to 0.72 and between QUS variables and BMD from r=0.30 to 0.36. BMD was the best discriminator of hip fractures (odds ratio = 3.61, area under curve = 0.824). All QUS variables were significant discriminators of hip fractures with odds ratios ranging from 1.88 to 2.63 and areas under the ROC curves ranging from 0.663 to 0.740. Among the QUS variables, the SOS_P showed the best odds ratio and area under curve. Comparison between the areas under the ROC curve did not show any significant difference between SOS_P, BUA and BMD. On the contrary, the difference between SOS_C and BMD was significant (P<0.05). In conclusion, BMD and QUS variables investigated in the current study were significant discriminators of hip fractures. The differentiation of the hip fractures by BMD was significantly better than that of BUA measured at the calcaneus. Moreover, BMD discriminated fractured patients better than BUA and SOS_P, although the difference did not reach statistical significance.

Keywords:  Osteoporosis, Hip fractures, QUS, DXA