Bone Fragility & Organic Matrix

Low energy trauma fragility fractures, often resulting from a simple fall from standing height or less, have a considerable human and socio-economic impact, morbidity, mortality and costs, and occur at all ages in children, men, and women. Thus, identifying patients that are at high risk of sustaining such a fracture is of great importance. To date, the only available clinical tool in the effort to identify such individuals is loss of bone mass, measured clinically as decrease in bone mineral density (BMD) by Dual X-ray Absorptiometry (DXA). Yet, despite concerted efforts, identifying patients that will sustain fragility (atraumatic or low energy) fractures remains a formidable challenge as it is well recognized nowadays that BMD measures do not capture all the contributing factors that result in fragility fractures, especially factors related to bone architecture and / or bone quality. As a result, as epidemiology studies clearly show, there is a considerable discrepancy between estimated fracture risk (based on BMD outcomes) and actual fracture incidence. One of the reasons for this is the fact that diagnostic methods employed in the everyday clinical practice focus on mineral considerations, yet bone is a composite material consisting of mineral, organic matrix, and water, thus its mechanical behaviour (especially resistance to fracture) is dependent on the quantity and quality of all three components. The proposed studies aim to bridge the gap between estimated fracture risk and actual fracture incidence by establishing the quality of the organic matrix in healthy and fragility fracture-sustaining patients irrespective of clinical diagnosis, as well as patients that are characterized by increased fracture risk yet do not sustain fragility fractures. The anticipated results will establish common bone material properties that are evident in patients with fragility fractures independent of age and clinical aetiology. This will help in refining definition of musculoskeletal diseases such as osteoporosis, and provide indices for the development of new and more focused diagnostic and therapeutic protocols.