Hip fractures kill and cripple far too many elderly women and
men. Every year roughly 350,000 people in the U.S. shatter their
hips and end up in the hospital, where more than 14,000 of them
die. Another 24 percent die within a year of the injury; half
lose their ability to walk. Most of these fractures, which cost
about $17 billion in medical care annually, result from a
withering of the skeleton known as osteoporosis. Physicians have
long used x-rays to estimate the density of bone minerals—a
rough indicator of bone strength. In 2011 the influential U.S.
Preventive Services Task Force, which sets testing standards
that Medicare and other health insurers tend to follow, began
urging all women to get an enhanced x-ray—known as a DXA (dual-
energy x-ray absorptiometry) scan—of the hip or lower spine to
check for small fractures or worn spots at age 65. The National
Osteoporosis Foundation suggests that all men have the same
screening scan by age 70. Although everyone benefits from such
baseline bone scans, most