Discordance between Hip and Spine Bone Mineral Density: A Point of Care
Byung‐Ho Yoon, Deog‐Yoon Kim
Abstract
Dual energy X-ray absorptiometry (DXA) is the most commonly used and validated method for the determination of bone mineral density (BMD).[1] DXA is usually measured at the central bone (hip and spine) and the BMD is determined by the lowest score at 1 of these 2 sites.[1,2] Discordance is defined as a discrepancy in the BMD measurements at the 2 sites, which can pose clinicians with the predicament on how to incorporate BMD measurement when deciding on the diagnosis and management of postmenopausal osteoporosis. Since its introduction in 2000, the World Health Organization has developed a classification system;[3] minor discordance indicates osteopenia at one site and normal or osteoporotic BMD at another, whereas major discordance indicates normal bone density at 1 site and osteoporosis at another.[4] T-score discordance can occur for a variety of reasons related to physiologic and pathologic patient factors as well as the performance or analysis of DXA itself.