Ultrasound measurements at the proximal phalanges in healthy women and patients with hip fractures

Measurements of bone mineral density (BMD) are useful for the assessment of fracture risk in osteoporosis. First prospective studies showed that quant itative ultrasound as measured at the calcaneus also predicts future hip fr acture risk, independently of BMD and as accurately as BMD. The aim of this study was to compile a reference population for a new ultrasound device th at determines amplitude-dependent speed of sound (AD-SOS) through the proxi mal phalanges of the hand and to prove its ability to distinguish between h ealth volunteers and osteoporotic patients. In a case-control study we exam ined 139 healthy women aged 21-94 years and a group of 24 female patients a ged 69-94 years with recent hip fractures. In the healthy reference populat ion additional BMD measurements were performed with dual-energy X-ray absor ptiometry (DXA) and quantitative ultrasound measurements at the calcaneus w ere carried out. In vivo precision of AD-SOS measurements through the phala nges was 0.52% CV. Simple regression analyses showed a negative correlation with age (r = -0.73, p < 0.001); modest significant correlations with BMD of the lumbar spine (r = 0.36, p < 0.001) and BMD of the femoral neck (r = 0.37, p = 0.002) as measured with DXA were shown. The comparison with anoth er ultrasound device measuring SOS and broadband ultrasound attenuation (BU A) through the calcaneus showed correlation with SOS (r = 0.50, p < 0.001); no significant correlation was found with BUA measurements. Furthermore a dependency of AD-SOS values in anthropometric factors such as body mass ind ex (r = 0.37, p < 0.001), height (r = 0.40, p < 0.001) and weight (r = 0.23 , p < 0.05) was shown. First study results on 24 clinically diagnosed osteo porotic patients, defined as patients with recent (<1 week) pertrochanteric or femoral neck fractures, showed a good separation between age- and sex-m atched controls and osteoporotic patients (Z = -2.0 SD). Receiver operating characteristic (ROC) curves showed an area under the fitted curve of 0.83 +/- 0.06. These results are powerful for a device measuring AD-SOS through the proximal phalanges of the hand, and further prospective studies have pr oven the capability of phalangeal ultrasound in fracture risk assessment.