Osteoporosis is a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture. An individual with a hip or vertebral fracture has an excess risk of death that is highest during the first year. Moreover, all osteoporosis related fractures can lead to significant long-term disability and decreased quality of life. The ability to accurately gauge fracture risk is critical in identifying cost-effective thresholds for intervention.
In 2008, the WHO Collaborating Centre for Metabolic Bone Diseases at Sheffield released the fracture risk assessment tool (FRAX) for estimation of individualized 10-year probability of hip and osteoporotic fracture (composite of hip, clinical spine, distal forearm, and proximal humerus) with or without BMD. The FRAX tool integrates seven clinical risk factors (prior fragility fracture, a parental history of hip fracture, smoking, use of systemic glucocorticoids, excess alcohol intake, body mass index (BMI), rheumatoid arthritis and other secondary causes of osteoporosis which, in addition to age and sex, contribute to a 10-year fracture risk estimate independently of BMD.
The importance of this tool in clinical practice is highlighted by the fact that many recently published clinical guidelines recommend pharmacological treatment on the basis of 10-year fracture risk. A key question that arises is the reversible nature of the risk that is identified. Several studies now demonstrate that patients at high probability of fracture have underlying low bone mass and respond to anti-osteoporotic therapies.