[Dual-photon absorptiometry of the calcaneum in osteoporosis. Preliminary results]

Anteroposterior views of the lumbar spine are commonly used for the measurement of bone mineral density (BMD) by diphoton absorptiometry (DPA). Values in lumbar vertebral BMD can be increased by the existence of a compression fracture, osteoarthrosis, scoliosis or aortic calcifications. Evaluation of bone loss at a peripheral site, such as the calcaneum (essentially trabecular site), could compensate for the principal causes of error associated with vertebral measurement. Calcaneal BMD in 195 control women was used to establish reference values closely correlated with lumbar BMD (p less than 0.001). The same study was undertaken in osteoporotic women. Preliminary results based upon 38 cases are reported here. Measurement of BMD of the calcaneum was correlated with vertebral trabecular bone density measured by double energy CT scan, indicating that this peripheral site offers a good reflection of what is happening at vertebral trabecular level. In contrast, calcaneal BMD was not correlated with spinal BMD, except if patients with osteoarthrosis and/or scoliosis were eliminated. Measurement of the BMD of the calcaneum by DPA is thus a simple, rapid and reproducible method for evaluation of a trabecular bone site which could be complementary to the measurement of lumbar BMD when the latter is falsified by artefacts.