Evaluation of osteoporosis using conventional radiographic methods and dual energy x-ray absorptiometry

Abstract

In India, conventional radiographs play a major part in evaluating osteoporosis since advanced bone densitometers are expensive and not widely available. Our aim in this study was to investigate the usefulness of conventional radiographic methods, viz., clavicle and metacarpal radiogrammetry, quantitative vertebral morphometry, Singh's index, hip geometry compared to a sophisticated method, viz., DXA for studying osteoporosis in south Indian men (n=663) and women (n=741). This study provides data on BMD of the proximal femur in normal south Indian females. In women, aged above 65 years, BMD of femoral neck, trochanter, and Ward's triangle decreased by 0.90%, 0.84%, and 1.66% per annum, respectively. In 45 pre- and post-menopausal women without fractures, total hip BMD correlated significantly ( p<0.001) with Singh's index [formula omitted] medial cortical thickness of the femoral shaft [formula omitted] and neck [formula omitted] combined cortical thickness (CCT) and %CCT of the clavicle [formula omitted] each), and the second metacarpal [formula omitted] and [formula omitted] respectively). On comparing variables studied for osteoporotic women with corresponding values in the premenopausal group, the average difference in SD from the mean was greatest for clavicle radiogrammetry (−3.7 SD for %CCT of the clavicle). An empirical formula for predicting total hip BMD with good sensitivity was derived from a multiple linear regression equation involving three independent variables, viz., CCT, %CCT of the clavicle (measured from the chest radiograph) and the patient's age. This author's equation, with modified weightings, has 82% sensitivity and 94% specificity and a positive and negative predictive value of 88% and 91% respectively. A chest radiograph in combination with the formula would serve as a readily available, inexpensive tool for assessing post-menopausal osteoporosis, especially in developing countries. © 2001, American Association of Physicists in Medicine. All rights reserved.