Fall 2011

Bionic Boomers? — New Joints Enhance Active Lifestyles

By Lindsey Getz
Aging Well
Vol. 4 No. 4 P. 10

Joint replacements allow boomers to maintain their active lifestyles well into old age.

Today’s older adults aren’t sitting in their rocking chairs on the front porch. They’re hiking, biking, golfing, and playing tennis. As a whole, society is increasingly active, perhaps contributing to the need for new knees, shoulders, and hips at a younger age. It used to be unheard of to have a joint replacement before the age of 65, but today orthopedic specialists report seeing more patients in their 40s and 50s.

In many cases, new joints allow older adults to stay active well into their later years. Some may joke that we’re creating bionic boomers, but the truth is society is slowly changing its views on aging. “Aging adults have a higher expectation as to what they can do activitywise, so we’ve adjusted our thinking to have a higher expectation as far as what implants are capable of doing for them,” says Matthew S. Austin, MD, director of joint replacement at the Rothman Institute at Thomas Jefferson University Hospital in Philadelphia. “We’re not really creating bionic people, it’s just that we’re no longer expecting people to sit and wither on the vine as they age. Arthritis doesn’t have to slow you down. A joint replacement can help patients get back to an active lifestyle.”

Total joint replacement surgery has been called one of the greatest surgical advancements of the last three decades. The life expectancy of new joints hovers between 15 and 20 years for 95% of the population based on published studies, reports Viktor Krebs, MD, director of the Center for Adult Reconstruction at Cleveland Clinic.

“There’s some research that suggests they may last even longer,” he adds. “The problem is that we don’t have enough long-term data on the replacements done many years ago to make an exact prediction. But we do know there are some knee and hip replacements that were put in 40 years ago and are still functioning today. A national registry will allow research on why certain implants last longer and what specific materials and designs work best, and will help us continue with the implant improvement process.” (See below.)

Winning Team
Joshua J. Jacobs, MD, chair of orthopedic surgery at Rush University Medical Center in Chicago, says it’s important for the primary care physician to work hand in hand with the surgeon performing the joint replacement surgery to ensure the best possible outcome for the patient. “We rely heavily on the primary care physician to ensure the patient is in good health—particularly good cardiovascular health—prior to surgery,” says Jacobs. “It should always be a team approach between that primary care physician and the surgeon.”

“Any medical problems should be optimized prior to surgery to reduce the risks involved,” says Austin. “It’s helpful, if a patient is overweight, for their primary care physician to help them embark on a weight-loss program. And in helping a patient select their surgeon, I’d advise that they look at a surgeon who has done a high volume of these procedures.”

The latter is critical, particularly in light of a recent study indicating that undergoing joint replacement in hospitals where relatively few of these procedures are performed increases a patient’s risk of developing complications. According to the study, published in the August issue of Arthritis & Rheumatism, blood clots were more common among patients at hospitals with low surgical volume, as were deaths within one year of the surgery.

On the Go
It’s boomers’ passion for high-impact activities such as running and basketball that wears out knees, hips, and shoulders at younger ages. As a result, these active adults are undergoing joint replacements so they can get on with their lives and continue with their on-the-go lifestyles, says Steven B. Haas, MD, chief of the knee service at Hospital for Special Surgery in New York City. “Patients tell me they don’t want to trade off their 50s just so they can prevent surgery in their 60s or 70s,” he says. “They want to continue with their active lifestyle now. If patients are restricting their activity and unhappy about it, then they shouldn’t have to wait for joint replacement surgery.”

Many doctors now consider waiting for surgery an outdated way of thinking. But it’s been only in recent years that the thought process has begun to shift. Not long ago, patients were told to “live with the pain.” It was believed patients should wait until they reached their 60s or 70s since a replacement might last only 15 to 20 years. Patients were encouraged to postpone surgery so they wouldn’t require more than one replacement. But data show that joints are lasting longer than expected and as materials continue to improve, it’s believed replacements’ life expectancy numbers will only get better. Today’s improved materials will likely extend the life expectancy well beyond the 20-year range, but no long-term data exist to substantiate that expectation.

Haas has personally been involved with the research and advancement of improved materials. In fact, the FDA just recently approved an implant referred to as the “30-year knee.” This new knee implant uses a hybrid material known as oxidized zirconium on the thigh bone side of the implant. The material is both smoother and harder than metal, so the wear rates (when the material rubs against a surface) are much lower.

“You can imagine that if you rub against a smoother surface that there would be less friction,” explains Haas. “As a result, this material is much more scratch resistant and resistant to in-body wear and tear.”

On the shin bone side, the materials have been improved by cross-linking the plastics during the manufacturing process. This means that on a molecular level, the chains of atoms comprising the material are bonded together, creating an even more durable structure. “By doing this, the wear rates become extremely low,” says Haas. “To give you some idea of the magnitude of this change, a simulated test that ran this new material for a simulation of 30 years was compared to the old material at a simulation of approximately three years. The new material still had 80% less wear than the old material, even though it ran more than nine times longer. Simulators aren’t perfect replicas, but they give you a reasonable idea of what wear and tear will be like on a joint—and that’s a significant change.”

New Surgical Techniques
Besides improvements in materials, orthopedic specialists are constantly examining ways to make joint replacement surgery less invasive. One possibility that has emerged for those suffering from knee arthritis is partial knee replacement. “Knee arthritis has a certain uniqueness to it,” says Michael J. Bronson, MD, FACS, vice chairman of the department of orthopedic surgery and chief of joint replacement surgery at Mount Sinai School of Medicine. “Unlike other joints such as the hip or shoulder, where arthritis sets in globally, what’s unique about the knee is that it’s comprised of different compartments. About one-third of patients who develop knee arthritis develop it on one side and are thus candidates for a partial knee replacement. For the remaining two-thirds, the appropriate treatment is a total knee replacement.”

There are some key differences between a partial and a total knee replacement. For one, while a total knee replacement would require a 6- to 8-inch incision, a partial replacement procedure’s incision is only 1.5 inches. But it’s the recovery periods’ durations where the differences really come to light. “With a total knee, the patient is in the hospital for four to five days and perhaps may go to a rehabilitation facility following their stay,” says Bronson. “But in a partial replacement, patients are typically home within 24 to 48 hours. And instead of four to six months of physical therapy, it’s more like four to six weeks. For older adults, many of whom have other health issues and don’t need the added stress of a major surgery, a partial knee replacement may be the ideal solution given that their arthritis is isolated to a unique compartment.”

Improvements continue among devices, procedures, and techniques. The buzz phrase “minimally invasive” pervades much of medicine today. In hip replacements, the latest news focuses on two relatively new procedures that claim to reduce complications and speed recovery. These include anterior hip replacement and the PATH technique. Comparisons of the long-term results between some of these minimally invasive techniques with the more traditional procedures have produced mixed results.

“If you look at the peer-reviewed data, there’s no long-term benefit from a minimally invasive approach,” says Krebs. “But it has made physicians more conscious about the size of their incisions and being more careful with the muscle than they were 10 years ago. While patients like to hear that the incision will be small, making it too small can sometimes be problematic because you never want to do a surgery blind and miss something. We’re also still waiting on peer-reviewed data for some of these minimally invasive procedures. I am convinced that the approach to a joint replacement needs to be individualized for the patient, and that in many situations, minimally invasive isn’t necessarily the best route. It’s important for every patient to discuss all the options with their doctor.”

Information Overload
It can be confusing to patients when new techniques and materials make big news. There have been cases where patients have specifically requested a joint replacement such as the “gender knee” based solely on marketing ploys and advertisements both online and on TV. Of course it’s critical that science continues to make advances that improve medicine, but Krebs says there’s also something to be said for proven technology that already has a track record.

“The challenging thing when it comes to anything innovative is that there isn’t the long-term data to support it,” he says. “And there’s always going to be something on the market that’s being called ‘better.’ Recently we have run into an unfortunate situation for patients related to a specific metal-on-metal bearing surface for hip replacement. The implant had a number of ‘new’ advantages but over time has resulted in early failure and a global recall. My best advice for physicians working with older patients is to direct them to a surgeon who has done a good number of joint replacements and uses a proven technology that already has those long-term results. If you’re 80 years old and I put a new hip in you that will last 20 years, then you’re set. Looking at the hottest new technology doesn’t always mean you’re getting what’s best for the patient.”

Jacobs agrees, noting that the wealth of information on the Internet about joint replacements can be an educational opportunity for the physician. “There’s a lot out there and it can be difficult for the patient to tease through and sort out,” he says. “I always stick by evidence-based medicine. I’d recommend that the physician counseling the patient also try to rely on evidence-based materials and not get caught up in the claims that are widely available on the Internet. Even more importantly, the surgeon doing the procedure is going to be the best source of information. They know how to sort out the claims that have been made and can help provide the patient with more realistic information about their own treatment and recovery.”

Postsurgery and Recovery
In addition to advancements in the surgical techniques and materials used in joint replacements, there has been progress made in the rehabilitation phase. “Some of the newer things taking place are ways to accelerate rehab,” says Austin. “We’re always looking at better pain management techniques. Today we’re able to make patients quite comfortable, which allows them to participate in physical therapy earlier. We use a combination of medicines, limiting the amount of narcotics because they can cause people to feel foggy, dizzy, and sometimes even nauseous. By limiting the side effects of narcotics, they do better in rehab.”

While these advancements have made the rehabilitation period easier in many ways, Krebs says it’s important that patients realize they will still need to take it easy and have some patience during the recovery process. He says this is another area where the Internet can be misleading.

“It can get difficult trying to pin down a recovery time for the patient when the Internet is telling them they can have joint replacement surgery and be back on the golf course in two weeks,” he says. “While we’ve improved and refined some of our recovery techniques, human beings have the same body and take the same amount of time to heal as they did 100 years ago.”

Krebs says keeping active prior to surgery—even though arthritis can make that painful or difficult—will help during the recovery period. “If you’re deconditioned because you haven’t moved for a year, it will take you longer to move again after joint replacement surgery than someone who was still active,” he says. “I’m cautious about giving people definite time frames for recovery because it can really differ, but it’s safe to say that the first four to six weeks post joint replacement is a healing and recovery time frame and that the activity following that is based on achieving physical fitness milestones. After the first four to six weeks, physical therapy gets much more aggressive. After three months, most patients typically start to get back to the activities they were having trouble doing with their worn-out joint. But patients should anticipate a full year to feel fully recovered and at their optimal level of activity.”

Following a joint replacement, patients can typically return to their previous level of activity when they feel ready. But the more impact they put on the new joint, the sooner it could wear out. “Most patients can resume the activity they did beforehand or maybe even do more with a new joint,” says Jacobs. “But many physicians that lean to the conservative side encourage patients to remain active without doing too much high-impact activity. If they do repetitive impact activities, the joint may not last as long.”

But Jacobs admits there are significantly differing opinions on that topic. Austin says the Rothman Institute puts no restrictions on their patients’ level of activity. And Haas says many of his patients are coming to him for joint replacements because they want to get back into high-impact sports. “Joint replacement used to be about doing the things you needed to do,” he says. “Now younger patients are coming and saying, ‘I want to continue playing tennis, skiing, golfing, or coaching little league, and I don’t want to be sidelined by pain or disability.’”

— Lindsey Getz is a freelance writer based in Royersford, Pa.

American Joint Replacement Registry
Though it’s long been talked about, tracking joint replacement data through a national registry may soon become a reality for U.S. orthopedists. This would foster a much greater understanding of what does—and doesn’t—work in total joint replacements.

In December 2010, the American Joint Replacement Registry (AJRR) launched with a proof of concept data collection, with the goal of identifying the methods for enrollment and data submission. After successful submission of level 1 data, the effort is closer to fruition.

The AJRR is a national, independent, not-for-profit organization intended to optimize patient outcomes through the collection of data on all primary and revision total joint replacement procedures in the United States. The mission of the registry is to improve patient safety, improve quality of care, and reduce cost of care. It’s strongly believed that learning from previous surgeries can help reduce revisions. The AJRR reports that registries in Sweden, Great Britain, Canada, and Australia have seen up to a 10% reduction in joint replacement revision rates.

In the short term, the AJRR hopes to create a real-time feedback mechanism to detect suboptimal joint performance. Ultimately, the AJRR seeks to establish an infrastructure and uniform system for collecting device information and monitoring outcomes of total joint replacement throughout the country. This would allow identification of patients who may need follow-up evaluation, thereby increasing patient safety.

Once operational, it’s expected that the AJRR will cost approximately $4 million per year. However, a group of surgeons, implant manufacturers, payers, medical societies, and other organizations will privately fund the registry. And since many physicians have long agreed that such a resource would greatly benefit the field, it hasn’t been difficult to generate interest among hospitals.

— LG