Why are hip, wrist, and spine fractures common in people with osteoporosis?

In people with osteoporosis, fractures of the hip, wrist, and spine are common because the disease causes the internal structure of the bone to become increasingly porous and fragile.1

As part of the aging process, the balance between bone formation and bone resorption shifts, leading to a net loss of bone mass and density. Within the bone, the tiny, rigid plates that form its honeycombed matrix become thinner and rodlike, while the spaces between them enlarge. This structural degradation significantly reduces the bone's ability to withstand mechanical stress.123

Because these bones are lighter and weaker, they are susceptible to fractures from minor traumas or stresses—such as simple movements, twisting motions, or supporting one's own weight—that would typically have no ill effects on healthy bone. The spine is particularly vulnerable to compression fractures, which can lead to a loss of height and the development of a "dowager's hump," while the hip and wrist are frequent sites of injury due to their role in supporting the body and absorbing impact during falls.1435