Technologies for the measurement of bone mineral density and other parameters of bone strength at peripheral skeletal sites have been studied since the 1960s. Single-energy Photon Absorptiometry (SPA), Radiographic Absorptiometry (RA), Radiogrametry (RG), Single-energy X-ray Absorptiometry (SXA), Peripheral Dual-energy X-ray Absorptiometry (pDXA), and Quantitative Ultrasonometry (QUS) have been successively evaluated. These technologies and their clinical applications are discussed in this article. The available scientific evidence supports the clinical use of these technologies at peripheral skeletal for assessment of fracture risk. Peripheral measurements other than the 33% (one-third) radius by DXA cannot be used to diagnose osteoporosis according to current standards. Peripheral skeletal sites are not clinically useful for monitoring changes in BMD with natural evolution of the disease and its treatment. Peripheral BMD measurement can theoretically be used to screen patients for selection to central DXA testing, although device-specific cut-points should be developed before this is implemented. When central DXA testing is not available, peripheral BMD testing may be considered to identify individuals who might benefit from pharmacological intervention.
Bone mineral density; Clinical applications; Peripheral DXA
