You, Too, Can Have A Bionic Body

Susan Burke's left knee was humbling her. At 54, she wanted to hike and whitewater raft through the national parks or, at the very least, to stroll around the block with her husband at night, as she'd always done. Instead, she could barely walk from her desk to her office parking lot without popping an Aleve. Her knee wouldn't leave her alone. Four years earlier, it had started swelling while she was training for an eight-mile trek through Glacier National Park. "I finally decided, 'All right, I'll get it checked'," she says. "The cartilage had worn down to the point of bone on bone." Burke's doctor told her she needed a knee replacement, but that wasn't what she wanted. It was too drastic, and she thought she was too young.

Over the next four years, Burke tried to salvage her knee with arthroscopic surgery, pain meds and lowered expectations for hikes that were "shorter than my usual horizons." But her knee was still crumbling. Finally, she met a fellow adventurer on a plane who had just had both knees replaced. He had a temporary cane, but he was young, in his 50s, and he seemed happy. Suddenly the idea of becoming bionic didn't sound so bad. "I thought, 'Geez Louise, maybe I should do something like that'," she says. In July, she did; her new right knee is made of plastic and metal. If you happen to be sitting next to her on a plane, she'll tell you that she has only one complaint: it's annoying to go through the airport metal detector.

Knee and hip replacements are serious surgeries, but increasingly, they're also a serious business. As the baby boomers' joints wear out, more of them are turning to orthopedic surgeons for the procedures. Docs now perform more than 450,000 knee replacements and 208,000 hip replacements a year, and rising numbers of them are done to boomers willing and able to pay $30,000 and up. By 2031, one study predicts, docs will perform more than 3.5 million knee replacements alone—a 673 percent increase from current numbers. It's as if an entire generation has taken Matthew 18:8 to heart: "If thy hand or thy foot offend thee, cut them off, and cast them from thee." And, apparently, sub in something better and keep going.

The boomers' embrace of replacement parts isn't entirely their choice—the fact is, they really need new parts. The most active generation in history, boomers gave us high-impact aerobics and the running craze, but at a cost. "We didn't know anything about the effects of high-impact activities when we were doing them," says Claude T. Moorman, an orthopedic surgeon and director of Sports Medicine at Duke University. "We didn't have good running shoes. We didn't understand the importance of strength. We didn't know about joint-preserving cartilage supplements." The result of all that zealous, uninformed activity: a generation with good overall cardiovascular health and wrecked hips and knees.

Joseph Zuckerman, chair of orthopedic surgery at the New York University Hospital for Joint Diseases, counts himself in that group. At 55, he's had to stop playing basketball and running. He hasn't had a knee replacement but admits he's "gonna need one." His case is sadly emblematic of many others: his left knee is bad partly because docs of the past made it worse. In college, he tore its cartilage; by medical school the knee hurt so much that he went to a surgeon, who took the cartilage out. It was a terrible idea, but the standard treatment at the time, says Moorman—doctors didn't realize that cartilage was a crucial shock absorber. "If patients didn't get better, the doctors assumed that meant they didn't get all the cartilage out," he says. But nature is "a heck of a lot smarter than we are, and that tissue was there for a reason. Some of the treatment quite honestly was worse than the disease."

Now, though, orthopedic surgeons can offer much better treatments. Most exciting is a strategy called "resurfacing," which has come to the United States within the last two years after proving successful in England. Well suited to active, younger patients, it holds back on replacing the entire joint (usually the hip), instead leaving a great deal of bone in place and covering it with a protective surface. "The pain relief is dramatic, even right away," says Moorman. And it doesn't require some types of traditional cement that can eat away at bone tissue, so it may be a more sustainable fix than a full replacement. Several new resurfacing devices are currently awaiting FDA approval.

In the meantime, old-school replacements have evolved, too—they're now made from more-durable plastics than they used to be. And surgeons have expanded their range. "There's a replacement for just about everything now," says Moorman. Shoulder implants have become mainstream, elbow implants are on the rise and ankle replacements have transformed from awkward devices into streamlined, highly engineered wonders made from light and durable material. "Twenty-five years ago, they didn't work very well and they didn't last, so we stopped doing them," says Zuckerman. "They came, and went, and now they've come back again." One recent case report on the new ankle replacements tells of a patient who, less than two years after surgery, went on "an aggressive hiking and fishing trip in Patagonia, where he was able to perform unlimited hiking at steep elevations and fish in rocky creek beds"—a success by any metric.

There's even a new take on the old stalwart surgery, the knee replacement: now it can be custom-made, a development that should surprise no one in the age of custom everything-else. "For 25 years we have put every replacement knee in at the same angle—your knee, my knee, my mother's knee," says Joseph Vernace, an orthopedic surgeon at Bryn Mawr Hospital, near Philadelphia. "The problem is, we're not all built the same." Using a new system called OtisKnee, pioneered by orthopedic surgeon Stephen Howell, docs can view the knee with MRI scans and superimpose different implants on it for the best fit. The early results on OtisKnee look good. Take Vernace's patient Terry Gibbs, who had his left knee custom-made in 2006 (and his right knee replaced traditionally five years earlier). "I went to a wedding six weeks after the [second] operation," he says, "and when someone asked me how I was doing, I did a deep-knee bend."

A word of caution, though: not all patients are out there doing deep knee bends. Most don't get back the range of motion they had when they were 18 (or 28 or 38). "The patient who comes to me and says, 'I can't run five miles anymore and I want an implant so I can do it again'—that's not who I'm going to do it for," says Zuckerman. Artificial joints wear out—the average life of a prosthetic is 15 to 20 years—and a patient who puts too much stress on his new implant may soon need another one.

Still, there's always hope. Burke, the outdoorswoman, is now walking more than a mile a day, an exercise she finds "liberating," if not quite liberating enough. What she really wants is "to get back to a national park and go for a nice big hike with my family." Yes, she has a new knee, but what really matters is her feet. She's back on them.