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Replaceable You

Can the system keep up with demand for new hips and knees?

It should have been a triumph of middle age.

In 2006, Glenn Kramon, assistant managing editor of The New York Times, flew to San Francisco to run the Bay to Breakers race with his Stanford roommate 30 years after the first time they’d run the 10K race as undergraduates.

They were thrilled to beat their original time. But about 10 days later, Kramon, then 53, awoke with a sharp pain in his right knee. After toughing it out for two months, he finally went to an orthopedic specialist who told Kramon (BA ’75) the problem was in his hip. Thanks to a congenital malformation and years of running, “My X-rays showed I had no cartilage left. The hip is like a tire, [the doctor] told me. Once you wear it out, there’s nothing you can do to fix it.”

Kramon tried supplements, such as glucosamine, chondroiton and fish oil; he stopped running and shifted to a stationary bike. The pain only worsened and, ominously, spread to his left hip. The only real solution looked to be a hip replacement, but his doctors gave him the standard advice: Wait as long as you can, because replacement joints also wear out, sometimes in 10 or 15 years for very active people. “But I was in agony,” says Kramon. “Getting into a car hurt like hell. So did putting on socks. So did walking. I couldn’t mount a bicycle without laying it on the ground and gingerly stepping over the crossbar. So I asked myself: Should I live in agony for a decade?”

Not only was his answer to that dilemma no, he insisted that his surgeon replace both hips at once. “I and others hope, possibly naively, that improvements in the technique and implants will make a second replacement, if necessary, more plausible someday.”

As the 77 million-strong baby boom generation moves out of midlife and into advanced age, nowhere are the physical, emotional, financial and social dimensions of our rapidly aging population colliding more poignantly than on the thin lining of cartilage in their hips and knees. Get ready: Kramon’s dilemma is going to occupy increasing amounts of media attention, cocktail party chatter and private soul-searching. Painful, largely unpreventable and lifestyle-threatening, osteoarthritis is an unwanted but sadly predictable consequence of a long, active life. It currently afflicts about 46 million Americans, and that number will hit 67 million by 2030.

The irony is that just when the medical consensus is increasingly clear that regular and, ideally, vigorous exercise is essential to virtually every aspect of growing old in the healthiest and most successful way possible, our joints appear to be conspiring against us. “Keeping people mobile is not only critical to personal health, but to allowing people to live independently and more economically,” says Anne Friedlander, PhD, an exercise physiologist who directs the Mobility Project at the Stanford Center on Longevity. The center is experimenting with a number of ways of helping people stay active [See “Just keep moving along,” this issue].

In the meantime, however, the most successful treatments we have today to restore function and halt immobilizing pain are complete knee and hip replacements. New technology and rehabilitation techniques are improving the recovery time and success of these procedures. But they represent a daunting and expensive threat to an already groaning health-care system.

At the heart of the matter is cartilage, a slippery, tough tissue well-suited to cushion impacts that allows our joints to move smoothly. But with age that cushion can begin to stiffen, roughen and wear out, allowing bones to rub together and create the swelling and pain of osteoarthritis. According to the Centers for Disease Control, arthritis is the leading cause of disability in this country, limiting the daily activities of roughly 20 million people and costing more than $80 billion annually.

Although people often believe that it is repetitive stress or the pounding associated with certain kinds of work or exercise that wears out knees and hips, experts say that exercise or repetitive activity alone has not been shown to cause arthritis in the joint. Rather, the degradation of the cartilage appears to be prompted by genetic factors, obesity and/or the result of a previous injury in which cartilage is damaged and then wears out more quickly with use. But the brutal fact is that cartilage does not grow back.

Since the 1970s, surgeons have been replacing hips and knees with implants made of titanium or chrome, ceramics and plastics. Today, about 600,000 Americans annually get a bionic joint. Technology and materials have improved; however, artificial knees and hips do wear out, sometimes in about a decade if the individual is very active.

Surgery is always risky, more so as one ages when the body’s ability to repair itself diminishes and other health factors may complicate recovery. For years, researchers have searched for a new way to handle arthritic joints that would leapfrog mechanical replacement parts. One idea is to try to use biotechnology to either get the body to generate new cartilage in place, or create healthy cartilage in the laboratory for transplant. “The problem with cartilage is that the body stops making it at around age 2,” explains William Maloney, MD, (BA ’79) chair of orthopedic surgery at Stanford and an expert in joint repair. Maloney is on the advisory board of one of several biotech companies trying to figure out a way to grow new, healthy cartilage, but he admits success in that area has been slow to develop.

Most patients begin treating the early aches and swelling of arthritis with ice packs and anti-inflammatory medications, gradually moving up to more powerful treatments, such as cortisone shots. Obese patients are urged to lose weight — a quest often thwarted by the joint pain that limits their ability and desire to exercise. Some patients try supplements such as glucosamine and chondroitin, and doctors inject hyaluronic acid directly into some joints to try to relieve pain. Side effects of those treatments are minimal; some patients report at least some pain relief, but they are far from permanent solutions.

Unfortunately, even if cartilage regeneration strategies can be developed, orthopedic specialists say they are likely to work best in younger patients with limited damage. “By the time a patient begins experiencing pain,” adds Maloney, “the disease process is pretty far along and a lot has gone wrong mechanically.” At that point, a replacement typically is necessary to return the patient to normal function. The hope is that special diagnostics will eventually pick up early, subtle, chemical changes at the beginning of cartilage damage, and that innovative new cartilage regeneration or repair treatments can be given before the joint is irreversibly damaged.

“I’m young and healthy and I want it fixed. My goal is to go backpacking with my family.”

What is increasingly clear today is that when severe osteoarthritis develops, active baby boomers are not about to surrender. Larry Fisher, 49, first banged up his knee shortly before coming to Stanford to play football in the late 1970s. He played three more seasons and had two surgeries, but by his late 40s, “There was just no relief,” says Fisher (BS ’81). “My right knee deteriorated to the point where I was favoring my other so-called good knee and that began hurting. I wasn’t able to go hiking with my family.” He toughed it out for a long time, but finally went to Maloney to learn about his options; by then he needed two new knees. “I said, ‘I’m young and healthy and I want it fixed. My goal is to go backpacking with my family.’” It worked. Eleven months after his 2006 surgery that replaced both knees at once, Fisher hit the Siskiyou wilderness with a 70-pound backpack, accompanied by his wife and two teenage children. He says the surgery and monthlong recovery were all worth it. “Within two weeks I felt better than I had prior to surgery,” he says. Adds Maloney, who did his operation, “Living with pain has become very unacceptable to us as a society.”

Strategies for rehabilitating joint replacement patients have improved quite a bit in recent years. It’s common for joint replacement patients to be up and walking within 24 hours of an operation, and aggressive physical therapy is key to speedy recovery. Robert Scheidtmann, a Menlo Park, Calif., pharmacist who had his right knee replaced in 2002, saw his doctor a week after his surgery and pretended to be angry that the doctor had lied to him when he said he’d spend three weeks in pain during recovery. “When does the pain start?” Scheidtmann demanded, breaking into a grin.

Probably more than most people, Scheidtmann knows he was unusually lucky. As a pharmacist, he’d seen hundreds of joint replacement patients hobble in and out of the drugstore for pain medications, including some who said they deeply regretted the operation and others who said they’d become dependent on pain pills. Although he had no regrets, Kramon admitted six weeks after his surgery that he felt worse than he looked, but said the surgery had restored his posture and relieved his preoccupying pain to such a degree that his friends said his face looked more relaxed. Knee and hip replacements are highly invasive procedures that carry risks of serious infection, blood clots and other dangerous consequences. However, a survey of 1,000 knee and hip replacement patients by Consumers Union in 2006 revealed that 82 percent said they were either “very” or “completely” satisfied with their new joints.

The painful truth for the U.S. health-care system is that it’s about to face an onslaught of patients demanding not only their first hip and knee joint replacements, but subsequent, equally expensive surgeries when those first artificial joints wear out. According to the American Academy of Orthopedic Surgeons, the number of first-time total knee replacements is predicted to increase by 673 percent to 3.48 million procedures by 2030, while primary total hip replacements will jump 174 percent. What’s more, the number of knee revisions will leap 522 percent and hip revisions another 237 percent as patients who receive the joints earlier and live longer experience artificial joint failure. Joint replacement surgeries can cost $30,000, and roughly half are covered by Medicare, but Medicare has cut its reimbursements to hospitals nearly 40 percent since the early 1990s. “We’re on a collision course between the demands placed by the Medicare population for services — joint replacement being a major one — and the ability of our society to pay for them,” says Joshua Jacobs, MD, chair of the AAOS Council on Research Quality Assessment and Technology.

As Maloney notes, advanced joint arthritis is irreversible and the sheer numbers of those over age 65 who will need hip and knee replacements are enough to fuel a big growth market. The new phenomenon is that younger patients are not willing to put plans on hold. Says Scheidtmann, who gave himself a new knee for his 60th birthday, “I realized there was a lot I wanted to do between 60 and 70 that required a good knee. I could have waited until 70, but there might be other reasons at 70 that would keep me from doing those things, and then I would have blown the chance.”

That attitude hasn’t been lost on makers of artificial joints who have launched direct-to-consumer advertising campaigns featuring sports celebrities, such as former tennis great Jimmy Connors and golf legend Jack Nicklaus. On a Web site sponsored by artificial knee and hip manufacturer Biomet, for example, former America’s sweetheart Olympic gymnast Mary Lou Retton explains how hip pain (from a congenital condition called hip displaysia) had driven her to a total hip replacement in her late 30s. “I went in with my list and said, this is what I want to be able to do,” Retton says in a video. “I don’t want to be limited after the surgery.”

It’s easy to see why such a message of empowerment would resonate with boomers. But Maloney is among many surgeons who have some discomfort about direct-to-consumer ads. In 2006, a study of orthopedic surgeons with experience in hip and knee replacement surgery showed that 77 percent expressed concerns about patients being confused or misinformed as a result of this form of advertising. “What happens is that you get patients coming in and saying, ‘I want the Jimmy Connors hip.’ Well, it may be that that particular product is not the best product for that particular patient, but they can get pretty set on it. You end up spending a lot of time trying to talk them out of something,” says Maloney.

“There’s nothing in medicine today that comes close to joint replacement when it comes to maintaining independence.”

Steve Grande, a 49-year-old printing company salesman from Long Island, insists his decision to get his hip replaced two years ago had nothing to do with ads or marketing. “It wasn’t cosmetic for me,” says Grande. “But I’m an aging yuppie who wanted to maintain my lifestyle. When I was told I needed a hip replacement, I just shook my head and walked out, but the pain gets worse and worse. I felt like I had a time bomb inside, and it starts taking over your character.” Grande says he asked every doctor he met whether there wasn’t some exciting new polymer or other agent that could just be injected in his hip and spare him the replacement surgery. “I kept hoping I could hold on, but they said, ‘Sorry, there’s nothing out there. This is a mechanical function we need to fix.’”

Doctors might resent implant makers using the same marketing techniques used to push sports drinks or sneakers, but they are quick to acknowledge that there is nothing frivolous or trendy about restoring mobility and the ability to exercise to people in middle age and beyond. Notes Maloney, “There’s nothing in medicine today that comes close to joint replacement when it comes to maintaining independence.” And he understands the emotional and personal dimensions of that firsthand: “I’ve had that little old lady come in who may be terrified of a hip replacement, but she knows if she doesn’t get it, she’ll have to go to a nursing home,” he says. “Believe me, she wants that hip.”

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Just keep moving along

Small steps in a variety of fields could help us stay on our feet

When you hear the word “mobility,” images of cell phones or laptops most likely come to mind. But to those trying to design a future for a rapidly aging population, it also means independence, health and happiness. They know that the ability to move around is critical to employment, brain function, cardiovascular health, proper weight maintenance, social relationships and living on one’s own. Getting and keeping individuals physically active is one of our society’s most important challenges.

That’s why one of the Stanford Center on Longevity’s cornerstone efforts is its Mobility Project, which is experimenting with ways to change the culture of this largely sedentary society, to convince people to get fit and stay independent.

“Most people know exercise is good for them. But what’s going on now clearly is not working,” says Anne Friedlander, PhD, who oversees the project. Not only are roughly 30 percent of U.S. adults obese, but studies show that despite concerted efforts from the government and others to increase physical activity, the number of people meeting minimum activity levels was the same in 2000 as it was in 1950.

Since mobility is not a traditional field of study, the project invites input from all across the university. Orthopedic surgeons, who enable mobility by replacing faulty joints, are important members. They include William Maloney, MD, professor of orthopedic surgery and chair of Stanford’s department. But project participants pursue many other approaches. Among them: exploring motivational strategies to encourage people to eat properly and get out and move; developing technology to help aging people compensate for natural declines in balance and strength to avoid catastrophic falls; and rethinking health-care strategies to lower barriers to exercise for those in pain.

The center is only 2 years old, and, to be sure, experts have been working on pieces of the challenge for a long time. Professor of immunology and rheumatology Kate Lorig, RN, DrPH, for example, has developed a model for helping people with arthritis pain increase their physical activity, network with other patients who share ideas and provide support, and educate themselves about their disease more cost-effectively. A six-week version of the program sponsored by The Arthritis Foundation was found to reduce pain by 20 percent in patients, and to reduce physician visits by 40 percent. Lorig believes that the medical community needs to help get more patients into programs like this and that individuals need to take responsibility for staying active so they can feel better and slow progression of their conditions. Compelling advice considering that arthritis has staggering costs, estimated at upward of $86 billion per year.

Thomas Rando, MD, PhD, associate professor of neurology and neurological sciences and deputy director of the longevity center, likes to think of the mobility challenge as spanning “cells to cities.” His own research is on the cellular level, where he investigates the mechanisms that undermine the ability of older people’s cells to repair themselves after injury. Meanwhile, Thomas Andriacchi, PhD, professor of mechanical engineering and of orthopedics, is focused on relieving joint pain and slowing the progression of osteoarthritis. He has developed a shoe to reduce the pain of osteoarthritis in the knee by shifting the pressure points inside the joint and curbing further degeneration. Now Andriacchi and the center are working toward commercializing the shoe — getting it manufactured and onto the feet of those who can benefit.

Says the center’s director, psychology professor Laura Carstensen, PhD: “We need practical and profound solutions to the most critical challenges of aging before both our nation and the global community face potentially devastating consequences.” Maintaining mobility throughout a person’s life span is one of those challenges.





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