Prediction of bone strength of distal forearm using radius bone mineral density and phalangeal speed of sound

This investigation compares quantitative ultrasound (QUS) measurement of th e phalanges with peripheral quantitative computed tomography (pQCT) and dua l X-ray absorptiometry (DXA) measurement of the forearm, to estimate the st rength of the distal radius in 13 cadaveric forearms. The cadavers were sca nned at the distal radius by pQCT and DXA for bone mineral density (BMD) an d at the approximate phalanges by QUS for speed of sound (SOS), The distal radii were subjected to a simulated Colles fracture produced with a materia ls testing machine, The load at which the distal radius was fractured was c onsidered as a representation of bone strength. The bone strength correlate d significantly with SOS at different phalanges (r = 0.63-0.72), BMD at dif ferent regions of interest by DXA (r = 0.67-0.75), and cortical BMD at diff erent sites by pQCT (r = 0.61-0.67), Standard stepwise regression analysis showed that adding phalangeal SOS into forearm densitometric variables sign ificantly enhanced the statistical power for prediction of the strength of the distal radius. Our results suggest that, for assessment of site-specifi c distal forearm strength, QUS measurement of the phalanges is comparable t o forearm densitometry, Phalangeal QUS may add clinical value if distal for earm strength has a high priority. (C) 2000 by Elsevier Science Inc. All ri ghts reserved.