PRECISION AND DISCRIMINATORY ABILITY OF CALCANEAL BONE ASSESSMENT TECHNOLOGIES

To determine if measuring skeletal status at the calcaneus is a potent ially valuable technique for diagnosing osteoporosis, we examined five calcaneal assessment techniques in 53 young normal women and 108 post menopausal women with osteoporosis and compared these measurements to dual-energy X-ray absorptiometry (DEXA)) at the calcaneus, hip, and sp ine. The five instruments, including single-energy X-ray absorptiometr y (SEXA) and four quantitative ultrasound (QUS) instruments, were eval uated for precision, ability to discriminate osteoporotic from young n ormal subjects, and correlation to the other instruments, The coeffici ent of variation (%CV) for instrument, positioning, interobserver, and short-term precision of the five calcaneal instruments ranged from 1. 34-7.76%, 1.63-7.00%, 1.84-9.44%, and 1.99-7.04%, respectively, The %C Vs for positioning, interobserver, and short-term precision were simil ar for calcaneal DEXA, calcaneal SEXA, and stiffness (as measured by A chilles), The %CVs for instrument precision were similar between calca neal DEXA and SEXA. The ability of the five calcaneal instruments to d iscriminate osteoporotic from young normal subjects was similar based on the analysis of area under the receiver operating characteristic cu rves (range 0.88-0.93) and equivalent to DEXA of the calcaneus and hip (0.88-0.93), The correlations between the measurements of five calcan eal instruments were strong (0.80 less than or equal to r less than or equal to 0.91,p < 0.001), These data suggest that although the precis ion is variable? the calcaneal QUS and SEXA instruments can discrimina te between osteoporotic patients and young normal controls and appear to be a useful technique for assessment of osteoporosis.