Flex Time

Doctors are no longer waiting decades to give patients new hips and knees. But before you trade yours in, there are a few things you should know. 

- Alice Oglethorpe

IF YOU’RE YOUNG, fit, and healthy, your body is supposed to move when you tell it to, right? That’s what Robyn Benincasa, a 40-year-old San Diego firefighter, triathlete, and all around badass, always thought. “Then one day, in the middle of a week long race of biking, kayaking, and mountaineering, my leg refused to take a single step,” Benincasa says. She’d had some pain in the front of her hips for two years, but assumed she’d pulled something that would eventually heal. She was wrong. A few weeks after her leg seized up, an orthopedic surgeon diagnosed Benincasa with advanced osteoarthritis in both hips. Translation: The cartilage that cushioned her joints had worn away, causing inflammation, pain, and stiffness that had finally stopped her short. After a few surgeries, Benincasa would eventually end up with two new hip joints.

Benincasa may have been 20 to 30 years younger than the typical hip-replacement patient, but women like her, who get a new joint before a pair of bifocals, are becoming surprisingly common: From 2000 to 2010, the number of total hip replacements in people ages 45 to 54 shot up 205 percent, and the rate of total knee replacements in people ages 45 to 64 nearly tripled.