Severe osteoporosis: diagnosis of non-hip non-vertebral (NHNV) fractures

Osteoporotic bone, structurally altered because of reduction of bone mineral density and quality deterioration, can easily head for fracture after minimum mechanical stress. The most common sites of fracture, other than spine and hip, are, in decreasing order: distal radius, forearm, proximal humerus, other femoral sites, ribs, pelvis, tibia and fibula, metatarsal bone and calcaneum. The role of diagnostic imaging is essential in detecting fractures for their immediate and correct assessment, which is necessary to the planning of treatment, whether conservative or surgical. Imaging is also important in fracture monitoring, evaluation of healing and relief of any complications. Conventional radiology is the most widely used technique in the diagnosis of fracture, although its low sensitivity, mainly in anatomically complex sites; the role of radiology is undisputed in monitoring the healing bone callus formation. Multidetector Computed Tomography (MDCT) is of great help in doubtful cases, especially in locations as "critical"; its diagnostic accuracy is very elevated with 3D and multi-planar reconstructions, allowing the surgeon to implement an appropriate therapeutic strategy. Magnetic Resonance (MR) is the most sensitive technique in the relief of minimal structural alteration of the cancellous bone, as it reveals both fracture line and surrounding bone marrow oedema. Its specificity is higher compared to MDCT and conventional radiology in the differential diagnosis between osteoporotic and malignancy pathological fracture. Bone scintigraphy is complementary to MRI in detecting occult fractures, crucial in finding metastatic disease in other locations. Ultrasound is used in limited districts, and its role is confined to the relief of cortical interruption in the fractured bone segment. In the future, technological advances with three-dimensional techniques (hr-CT, hr-MRI) may improve in vivo the diagnostic potential with an earlier detection of the ultrastructural alterations that predispose to the risk of bone fracture.