[The fracture risk in the elderly subject: the determining factors]

Recent advancements in the field of bone mass measurements allow us a precise determination of bone mineral density values in various skeletal sites. At present, their determination gives the most valuable information on individual fracture risk. However, we sometimes to witness fragility fractures in presence of regular values of bone mineral density which suggest a satisfactory status of skeletal mineralization. These cases underline that the mechanical incompetence of the skeleton is not simply the result of a decrease in bone mineral density and that other factors are responsible for the increase of fracture incidence in the elderly. In this paper, several factors potentially involved in the occurrence of fragility fractures in elderly people have been considered on the basis of the most recent data of the current literature in this field. These factors, subdivided in bone tissue extrinsic and bone tissue intrinsic factors, include: muscle synergisms, reflex reactions and sensory status, soft tissue features, bone tissue features, structural properties and loading modalities in relation to structural orientation. Awareness and analysis on these factors are important for better management of preventive as well as therapeutic measures for fragility fractures in elderly.