The New Knee Replacements Read This If You’re Considering Joint Replacement Surgery

If knee pain constantly bothers you, the prospect of joint replacement surgery can be tempting. In fact, a new study shows that more and more women younger than 60 are opting for knee replacements. Why the popularity? And are they a good idea? We get the scoop from top arthritis experts... Knee osteoarthritis. It can start out as an occasional twinge that eventually becomes a constant pain, making it difficult to walk, stay active or just get through the day. And when joint degeneration starts affecting your life, you may start thinking about surgery. You’re not alone. Knee replacements have become increasingly common among younger women, according to a January 2012 Finnish study published in Arthritis & Rheumatism. Researchers at Helsinki University Central Hospital found that in Finland, the number of knee replacements in people ages 30-59 in 2006 was 130 times more than it was in 1980. And women had as many as 2.4 times more replacements than men. The numbers jibe with American figures: More than 600,000 total knee replacements were performed in the U.S. in 2009, says an editorial accompanying the Finnish study co-written by Jeffrey N. Katz, M.D., professor of medicine and orthopedic surgery at Harvard Medical School. The number has doubled since 1999, according to a February 2012 presentation to the American Academy of Orthopaedic Surgeons, which said that 5.3% of women and 4.1% of men over 50 currently have total knee replacements. The fastest-growing age group was 45-64, Katz says. Read on to learn what you need to know about knee replacements. Knee Replacement Fact #1: Why They’re Becoming More Popular Joint replacement surgery is so popular, experts say, because of reasons that include: Technological advances. Surgeons have become more comfortable performing these operations on younger people. “Thirty years ago, surgeons wouldn’t do knee replacements in people under 60,” says Douglas Garland, M.D., medical director for orthopedics at MemorialCare Joint Replacement Center at Long Beach Memorial Medical Center in California. But now, “our equipment is better, and we don’t worry about [knee replacements] wearing out like we did 30 years ago.” In the past, knee replacements used cement that commonly broke down, but today’s metal and ceramic parts are more durable, he says. In fact, 90%-95% of knee replacements now last 15 years or longer, according to the American Academy of Orthopedic Surgeons (AAOS). Osteoarthritis strikes at an earlier age. Younger women are developing arthritis pain, possibly because of the strain of carrying extra pounds, Garland says. Nearly two-thirds of American women are overweight or obese, according to the National Institutes of Health. “Obesity is the No. 1 cause of knee osteoarthritis,” he says. “And the younger and fatter you are, the earlier your joints will wear out.” Each step puts a force on your knee equal to six times your body weight, Garland says. So gaining 10 pounds adds 60 pounds of pressure to the joint. Women have worse knee problems than men. That’s partly because estrogen plays a role in the laxity, or looseness, of joint ligaments, researchers say. They point to rising levels of the hormone during pregnancy, which allows pelvic ligaments to loosen for childbirth. “[Women] have a laxity in the joints [related to] estrogen, and less muscle mass than men,” Garland says. “So their joint is less stable than a man’s.” That makes women more prone to micro-trauma – tiny injuries to the bone – which is the second-leading cause of knee osteoarthritis, Garland says. Baby boomers want to stay active. That means older adults are suffering more activity-related knee injuries that increase arthritis risk, says rheumatologist Nathan Wei, M.D., director of the Arthritis Treatment Center in Frederick, Md. At the same time, they’re more willing than previous generations to have joint replacement surgery if they think it will keep them going. “Boomers have a sense of entitlement to a more active lifestyle,” he says. “They’re not going to let something [like knee pain] stand in their way.” A lack of other choices. When it comes to knee pain, there’s isn’t much that can be done between conservative treatment – such as nonsteroidal anti-inflammatory drugs and steroid injections – and the more drastic joint replacement surgery, Wei says. “Nothing fills in the gap,” he adds. “Until we have something, like stem cells, that’s proven to regenerate cartilage and prevent [the need for surgery], we’re going to continue to see a surge of knee replacements in active people.” Knee Replacement Fact #2: You May Be Able to Prevent It If you want to prevent or postpone joint replacement surgery, there are steps you can take now: Drop pounds. “Weight loss may help avert severe osteoarthritis,” Katz says. Not only does added body weight put extra pressure on your knees, the fat tissue itself secretes protein messengers called adipokines that stimulate inflammation, Wei says. People with knee osteoarthritis who lost 11.4%of their body weight experienced nearly 50% less pain, according to 2011 research at Wake Forest University in Winston-Salem, N.C. Exercise. “I give patients a simple formula: Good medications, ideal weight and regular exercise equal good-feeling knees,” Wei says. If you’ve never exercised, he advises starting out just a minute or two a day, then building up gradually. Incorporate three types of exercise: cardio (aerobic exercise that increases your heart rate), strength training and stretching. Women with the strongest thigh muscles were 50% less likely to develop knee pain compared with those with the weakest, a 2009 University of Iowa study found. “You need to do some type [of exercise] every day, working up to as much as you feel comfortable with,” Wei says. “Make sure it’s a habit, like brushing your teeth.” Garland advises his patients to walk 20-30 minutes every day to strengthen the muscles in their legs and knees. “And if you want to lose weight, walk for an hour,” he says. But avoid high-impact exercises like jogging or basketball, which can make knee pain worse, Wei warns. If you like tennis, play doubles, Garland suggests. “You’re not [twisting] the knees as much.” You can find exercises designed specifically to strengthen the knees on the AAOS’ website. Also, check out 5 Pain-Relieving Arthritis Exercises. Knee Replacement Fact #3: It May Not Be Permanent Knee replacements don’t necessarily last a lifetime. At some point you may need another operation, known as a “revision.” “If we look at people who’ve had knee replacements for 10 years, 95% have had no problem,” Garland says. “But right now, we really don’t know the lifespan of knee replacements.” The need for a second replacement is greater among younger women. “Rates of failure leading to revision in younger patients are two-fold higher than in older patients,” says Elena Losina, Ph.D., associate professor of orthopedic surgery at Harvard Medical School and co-director of the Orthopaedic and Arthritis Center for Outcomes Research at Brigham and Women’s Hospital in Boston. That’s because they run a greater risk that the first implant will fail – and, of course, they have more time to outlive the first joint replacement, she says. Knee Replacement Fact #4: You May Not Need a Total Replacement In total knee replacements, all three “compartments” in the knee, which are formed where the various bones meet, are removed and replaced. But partial knee replacements – in which the surgeon removes and replaces only the damaged areas of knee cartilage in one compartment – are also increasingly common. In the short term, a partial replacement is more likely to make it easier for you to do things like climb stairs or kneel. “Partial knee [replacement] may have better functional outcome and earlier recovery after surgery,” says Jarkko Leskinen, M.D., an orthopedic surgeon at Helsinki University Central Hospital in Finland and lead author of the Finnish study. But it’s also more likely to require a second operation, or revision, than a total knee replacement. And at that point, the joint is likely not to function as well as it would have after a single total replacement operation. Talk to your doctor about which kind of surgery is best for you. Knee Replacement Fact #5: How to Care for Your Knee If you do opt for joint replacement surgery, here's how to make your knee last as long as possible: Stay at a fighting weight. The same things that prevent knee osteoarthritis from getting worse also slow down the wear on your replacement, Garland says. “If you’re 50 and overweight, your risk of revision will be high,” he says. “[But] if you can maintain a near-ideal body weight, that’s the best thing you can do for your joint.” Keep leg muscles strong. “Good muscle tone [is also important] to avoid another joint replacement,” Garland says. Many joint replacement programs, including the one at MemorialCare Joint Replacement Center, get patients up and walking the same day of surgery, he says. Physical therapy can help, he adds. Following surgery, “we start an outpatient therapy program on machines so patients can start building their muscles back.” But skip leg squats and lunges. “Deep knee bending isn’t good for the knee, before surgery or after,” he says. “It’s hard on the joints.” Avoid triathlons. Physical activity is important to overall health, but when it comes to knee replacements, moderation is key, says Losina, who co-wrote with Katz the editorial in Arthritis & Rheumatism. “The more active you are, the shorter the lifespan of the replacement,” Wei adds. Still, Garland says, “I’d never say no to an activity if it’s important to the patient psychologically.” Get picky about your surgeon. Make certain your orthopedic surgeon specializes in knee replacements and that the hospital offers a good rehabilitation program, Wei says. Garland suggests choosing a surgeon who averages at least one joint replacement a week, preferably two. “Busy surgeons are usually good surgeons,” he says. For more information, visit our Osteoarthritis Health Center. Are You Bad to the Bone? For years, you’ve been the first one on the tennis courts, the weekend hiker, the intrepid gardener on your knees for hours. Though all those activities are great for you, they can also be hard on your joints.