RIGHT AND LEFT PROXIMAL FEMUR ANALYSES - IS THERE A NEED TO DO BOTH

The purpose of this study was to determine if differences existed betw een right and left proximal femur bone mineral density (BMD) in a grou p of women. Participants for the study were 198 women ranging in age f rom 16 to 73 years. Bone mineral densities of both proximal femurs (fe moral neck, Ward's area, and trochanter) were assessed using dual ener gy X-ray absorptiometry (Lunar DPX). Mean (+/-SD) age, height, and wei ght of the participants were 32.9 +/- 18 years, 164 +/- 7.4 cm, and 64 .9 +/- 12.1 kg, respectively. Significant differences between right an d left femoral BMDs were found only in the trochanter. Overall, mean d ifferences in BMD were low (neck = 0.7%, Ward's = 0.2%, and trochanter = 1.9%) but individual variations were as high as 22%. Based on BMD z -scores of <-1.0, 84 women were classified as ''at risk'' for osteopor osis. When right and left z-scores were compared, misclassifications o f at risk women were 4, 15, and 11 for neck, Ward's area, and trochant er, respectively. In conclusion, analyses of both right and left proxi mal femurs may not be necessary for either the researcher or the clini cian.