Osteoporosis: epidemiology and available diagnostic approaches

Osteoporosis is the most common disorder of bone metabolism, with a high rate of diffusion, especially in the elderly population. The main consequence of osteoporosis is bone fragility, with the consequently increased risk of fracture. Vertebral and hip fractures represent one of the most important causes of morbidity and disability and cause also high economic costs for the National Healthcare Systems. The currently accepted "gold standard" method for osteoporosis diagnosis is represented by the evaluation of bone mineral density (BMD) through dual X-ray absorptiometry (DXA). However, DXA presents some considerable limitations such as the exposition to ionizing radiations, employment of bulky devices and high costs of management. This paper gives an overview of the most widely used X-ray based techniques to perform osteoporosis diagnosis and describes the working principles of non-invasive ultrasound (US) based methods for bone densitometry, underlining the corresponding advantages and limitations for their use in the clinical practice. Moreover, the article illustrates the effectiveness of an innovative US technique, directly applicable on the main anatomical reference sites, in terms of diagnostic accuracy and fracture risk prediction. Early diagnosis is the key to resize the impact of osteoporosis on healthcare systems. Therefore, it would be necessary to encourage the widespread use of quick, cheap and non-invasive screening techniques.