DUAL X-RAY ABSORPTIOMETRY OF THE PROXIMAL FEMUR - NORMAL EUROPEAN VALUES STANDARDIZED WITH THE EUROPEAN SPINE PHANTOM

Measurements of the proximal femur by dual X-ray absorptiometry (DXA) are assuming increasing importance in clinical and epidemiological stu dies. However, different DXA manufacturers have adopted varying approa ches to measuring the femoral neck and trochanter regions with the res ult that there is as yet no agreement on normal ranges and how to cros s-calibrate between different machines. In this Concerted Action (of t he EU's 2nd Framework Programme), 12 clinical centers in eight countri es recruited a total of 855 female and 517 male Caucasian subjects who were judged to be free of conditions known to cause secondary osteopo rosis and who had not been treated with drugs known to affect bone mas s. The DXA machines used were made by Hologic, Lunar, and Norland. Eac h machine was cross-calibrated with the European Spine Phantom prototy pe designed by Kalender. Ah femoral neck and trochanter results were e xpressed as standardized values and were first examined for possible b ias due to between-brand differences in choice of areas for measuremen t. On average, trochanter areas were similar between brands but Norlan d chose a narrower neck region for analysis. Bone mineral density (BMA or BMD g/cm(2)) was log-normally distributed for all groups at the fe moral neck but normally distributed at the trochanter in men and postm enopausal