Pathophysiology of Fractures

Summary

• There are multiple determinants of fractures, many of which are related to each other by virtue of their increased prevalence with aging.

• Osteoporosis (or low bone mass) is a major risk factor for fractures, but it is not the only factor.

• Appropriate strategies for decreasing fracture frequency include both pharmacologic and non-pharmacologic approaches, which address the wide variety of risk factors for fracture with which our patients present.

Fractures are the complication of osteoporosis, much as strokes are the complication and result of hypertension. It is only through fractures that osteoporosis manifests its clinical effects or has clinical relevance. Fractures occur in patients with decreased bone strength and who experience an injury. Thus, the pathophysiology of fractures encompasses a multitude of factors that determine bone strength (bone mass, bone quality, age, skeletal geometry) and the frequency, nature, and effects of injuries (Figure 4.1).Each of these factors becomes more prevalent with advancing age, resulting in the exponential increase in the prevalence of fractures related to osteoporosis in elderly individuals. Understanding the determinants of fracture risk provides the basis of appropriate and effective interventions to reduce fracture frequency and the complications of osteoporosis.