 Osteoporosis is a systemic bone disease characterized by low bone mass and microarchitectural deterioration of bone tissue with consequent bone fragility and susceptibility to fractures. Fifty percent of women and 20 of men older than 50 y.o. will have an osteoporotic fracture fragility fracture. Fragility fracture is defined as one that results from a low-energy trauma such as a fall from body height. A previous fracture is an important predictor of a new fracture, especially in the first 5 years after the initial fracture. A second fracture can be particularly devastating if a hip fracture. Approximately 25 of individuals with hip fracture die in five years and only half of them recover the pre-fracture status, meaning loss of ambulation ability and independence in domestic activities. In addition, fragility fractures generate significant cost to the health system - the annual cost of osteoporotic fractures in patients older than 50 years in the United States is estimated at 1.3 billion dollar. 