Does combining the results from multiple bone sites measured by a new quantitative ultrasound device improve discrimination of hip fracture?

There is a growing interest in the use of quantitative ultrasound (QUS) mea surements as an alternative to current radiation-based bone densitometry te chniques for the noninvasive assessment of fracture risk. While most of the commercialized ultrasound devices measure only single predefined periphera l skeletal sites, the Omnisense prototype (Sunlight Ltd., Israel) can be us ed on multiple bones, including the spinous processes. in this study, we ex amined the ability of speed of sound measured at the calcaneus, distal thir d and ultradistal radius! proximal third phalanx, metacarpal, capitate, pat ella, and the posterior process of the thoracic spine to differentiate subj ects with hip fractures from normal controls. Seventy-nine postmenopausal C aucasian Israeli women who had sustained an atraumatic fracture of the prox imal femur within the last 6 months were recruited from the local populatio n (mean age 80 +/- 8.9 years). As controls, 295 postmenopausal Caucasian Is raeli women without osteoporotic fractures were also included (mean age 70 +/- 8.7 years). Discrimination Of hip fractures with QUS at all ultrasound sites tvas highly statistically significant (p < 0.01) (odds ratios [ORs] = 1.4-3.0; area under the ROC curve [AUC] 77-92%), except for the hand metac arpal. Distal radius and calcaneus measurements (ORs = 2.4 and 3.0) were th e best discriminators of hip fracture patients from controls. Using a forwa rd selective linear regression model, the discriminator values of combined assessment at two sites were investigated. There was moderate improvement i n diagnostic value, but the best combination was the calcaneus with the dis tal radius, which improved the AUC by 3% and raised both the sensitivity an d specificity to 94%. These data demonstrate the encouraging potential of i mproving discrimination of hip fracture by using multiple-site ultrasonic m easurements.