Dual X-Ray Photon Absorptiometry: Beyond the Bone Quantity?

Osteoporosis is a characterized by low bone mass and microarchitectural deterioration, with a consequent increase in bone fragility [1]. Bone strength impairment leads to an increased risk of fracture, as strenght reflects the integration of bone quantity (bone mineral density, BMD) and bone quality [2]. Common sites of osteoporotic fractures are spine, hip, distal forearm and proximal homerus. These fractures determine high rates of disability and mortality: 50% of fracture-related deaths in women are due to hip fractures, 28% to clinical vertebral fractures and 22% to other fractures [1]. Twenty percent of hip fractured patients, die within the following year and 20% require permanent nursing home care [3,4]. Vertebral fractures are the most frequent fractures in osteoporotic patients, and are associated with substantial disability due to compromised spine dynamics and static biomechanics. Furthermore, their number and severity are related to an exponential increase of subsequent fractures [5].