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Artificial joints and the surgery to install them have improved enough that patients in pain can get relief earlier. Once, they would have delayed surgery as long as possible because the new joints might wear out.
By WES ALLISON
© St. Petersburg Times, published August 9, 2000
ST. PETERSBURG -- Wayne Desmarais, a sergeant for the Pinellas County Sheriff's Office, knew the risks of getting a new knee at his age. At 50, he was young for the procedure, and the replacement joint never would be as strong as his own. And because artificial joints don't last forever, he might need another before he retired.
But the pain and immobility of his left knee, which he injured in an accident in March 1998, had become all-consuming. X-rays showed that the bones that meet at the knee, the femur and the tibia, were grating together each time he moved it, and the cartilage that was assigned to protect them had crumbled away.
His knee was drained routinely. He couldn't sleep. His mood, because of the aches, at times turned rotten. Finally, he told Dr. Steven Warren: Do it.
"The pain was constant. I walked like a bow-legged old man," Desmarais said. "I couldn't stand the thought that (co-workers) couldn't count on me to pull them out, or that I wouldn't be there for somebody."
Warren replaced the joint in Desmarais' left knee March 1. After his most recent checkup in July, X-rays showed a clean, smooth contact between his femur and tibia where the implants meet. The physical therapy was tough, but his knee now feels as good as the X-ray looks.
"He told me the rehab would be strenuous, that I'd probably be calling him names," Desmarais said. "Other than the scar, you wouldn't ever know I had surgery."
In the past 20 years, joint replacements have become standard treatment for many people with serious injuries or the type of painful, mobility-robbing arthritis that often comes with age. Local doctors have volumes of files on seniors for whom even shopping had become impossible, but who now can walk daily, or play golf or bike.
The walls of Warren's office include photos of a competitive ballroom dancer, age 84, with a new right knee, and of a man in his late 70s with two new knees and a new hip, who also is a nationally ranked doubles tennis player.
Except in cases of rheumatoid arthritis, an immune disorder, and injury, many doctors have been reluctant to replace the joints of middle-age people whose knees or hips were stiffened by arthritis or years of pounding from work or sports.
Prosthetic joints tended to wear out in 10 to 15 years, and replacing them -- an operation known as a revision -- was neither easy nor especially successful because so much bone was damaged during the original operation.
Better materials and advanced techniques, including some that are brand-new, are beginning to make joint replacements more feasible for younger, active people such as Desmarais who want to continue to work and play hard.
"We're basically doing them on younger and younger patients, because the success we've had in older people has empowered them," said Dr. Thomas L. Bernasek of the Florida Orthopaedic Institute in Tampa, who does about 500 total-joint replacements a year.
"When I first started practicing, we'd say to people, "Wait as long as we can.' Then you become this age and you realize, why am I going to make them wait 10 years? By then they've missed their best earning years, they've missed their family years, sitting on the couch."
Doctors view the trend with a mixture of delight and trepidation: They like the prospects of helping more people live fuller lives, but they also worry aging Baby Boomers will wear out their new joints, then be disappointed if technology can't bail them out.
Dr. Bernard Morrey, a professor of orthopedics at the Mayo Clinic in Rochester, Minn., which did the first total hip replacement in the United States in March 1969, said it's become more common for middle-age people to seek replacements, even if their joints aren't in bad enough shape.
As long as the patient truly needs surgical relief, he's also more likely to perform one.
"There's an increasing interest on the part of our society that demands earlier intervention," said Morrey, who has practiced at Mayo for almost 20 years.
"It goes back to the notion that we're not willing to take physical discomfort, and we're not willing to give up the things we want to do. In the past, the (joint replacement) didn't necessarily mean they would be able to go back to high levels of activity. So they would just live with it."
Penny Lucier, 48, couldn't imagine simply living with it. Years of athletic pounding obliterated the protective coating of cartilage in her left knee, making each step a painful grate. She could barely negotiate stairs.
For the athletic director and tennis pro at the Jewish Community Center in Tampa, that wouldn't do.
"I didn't want to live another 20, 30 years and then have it done, and dismiss from my life being active," she said.
Dr. Michael Wasylik, chief of orthopedics at St. Joseph's Hospital, replaced her left knee last year, and he warned her she'd have to slow down. Doctors say people with hip or knee replacements generally can play doubles tennis, golf, bike, swim and walk. Physicians tend to advise against pounding activities, including jogging, skiing and basketball.
Lucier is back to coaching tennis as well as playing doubles, and even singles, though it makes her doctor wince to hear it. The replacement knee cost her some ability to scoot from side to side, but otherwise it feels and works great, she says. A recent X-ray showed it looks good inside, too.
"He really told me, "Penny, if you take good care of it, and you don't jump on it, and you don't beat on it, it'll last,' " Lucier said. "I am so active, I'm a hard one to keep down. But I'm not real concerned about it."
At the St. Petersburg offices of Tampa Bay Orthopaedic Specialists, Warren holds a model of a newly rebuilt knee. The shiny metal cap imbedded in the femur and the slick plastic cap on the tibia allow the knee to bend and straighten effortlessly. Painlessly.
By the time most patients need this replacement, "The areas that used to glide cartilage to cartilage are . . . now grinding like rock against sandpaper," Warren said.
The basic tenets of joint replacement surgery haven't changed all that much since the hip replacement was developed and tried, with mixed success, in England more than 40 years ago. In a full hip replacement, the natural ball-and-socket joint is dislocated, and a metal or plastic cup is fitted into the socket in the pelvis.
The old ball is cut off, and a metal one is implanted into the end of the bone. The ball is snapped into the socket, the incision is stitched up, and the patient can usually go home from the hospital in about four days. Physical therapy strengthens the muscles around it, which helps hold the joint together.
The knee replacement is similar, although there's no ball-and-socket joint. The kneecap is removed, and metal or plastic caps are imbedded into the bottom of the femur and the top of the shin bone, the tibia, replacing the worn cartilage and providing a smooth hinge. The back of the kneecap also is resurfaced with plastic.
The joint is held together naturally by ligaments and muscle, but intense physical therapy is imperative.
The operation is extremely common, with about 245,000 knee and 240,000 hip replacements performed in 1996, the most recent year for which data is available, according to the American Academy of Orthopaedic Surgeons. That's almost twice as many as five years before.
The success rate for both knee and hip replacements tops 90 percent. Still, the procedure carries a small risk, especially for the elderly and persons with health problems. Infection is the biggest danger, and it can occur right after the operation or years later.
Some people are not good candidates for the surgery, at least not yet. Doctors say it's best to put off surgery until more conservative measures, including medicine, physical therapy and a walking aid, no longer help.
Dr. Frank Vasey, chief of rheumatology at the University of South Florida and the James A. Haley VA Medical Center, treats arthritis sufferers before they see an orthopedist, and he tries to make sure they know the risks before settling on a replacement.
"It's harder to repeat the procedure a second time. That's why everyone tries to delay it as much as possible," he said. "With younger patients, they need to realize that they need to treat these joints with respect. They're not your normal joints."
A replacement joint typically is made of super-hard metal and a high-density plastic. The combination allows for excellent mobility without pain, but over time the metal will begin to wear away the plastic, depending upon the weight of the patient and the stress she puts on it.
That makes the joint looser and less functional. Debris from the plastic also builds up around the bones. That can cause the immune system to attack, leading to a condition called osteolysis in which the bone is eaten away, until it resembles Swiss cheese.
Bone also is sacrificed during the operation to make room for the prosthesis, and installing or removing hardware can damage bone as well. So if a hip or knee wears out, especially if you suffer from osteolysis, there may not be enough bone to securely hold a new one.
Like anglers who argue which bait is best, orthopedic surgeons don't always agree on methods or materials. But they do agree that the materials are improving, even since Penny Lucier had her surgery in January 1999, and several new variations on old designs may make the joints more durable.
That's good news for today's 40- and 50-somethings who may need them in 20 years.
"The whole idea with all of them is either to make a bearing surface that is very hard and basically does not wear, or if it does wear, that the it wears so slowly that ... problems don't come into play for decades," Bernasek said.
"We always talk with optimism that technology will take us further. This is one very excellent example where even in the last five years we've seen vast improvements in our materials."
Not only younger people are benefitting from better materials. Irene Gonzalez, 84, was a champion ballroom dancer who kept putting off her knee replacement because she feared that, with an artificial joint, she couldn't compete again. She had minor surgery to clean up the frayed cartilage, but it didn't help much.
"The cartilage was gone, and the bones were rubbing. Because I wanted to keep dancing, I really stalled," she said. "But I still had so much pain, and the knee kept giving out, and I would fall. I thought, "Great, the next thing I know I'm going to crack my head or my hip.' "
She finally had the operation about two years ago, and the knee's durability and strength has surprised her. The foxtrot, the Viennese waltz, the cha-cha, you name it: She hits the floor almost every day.
"Two doctors had told me if I had the knee replaced, I'd be able to dance, but I'd never be able to dance in competitions," she said. "But I've done it ever since I had the knee replacement."
Nothing is as tough or friction-free as natural cartilage, but some materials are getting closer, doctors and researchers say:
Highly cross-linked polyethylene: A slick and super-hard plastic. Most artificial joints implanted today feature metal on polyethylene, and the plastic is constantly is being improved. Mechanical tests have showed the latest version could last 27 years.
Ceramic on ceramic: Ceramic parts were tried in years past, but they were largely abandoned because they proved to be too brittle. Better-made ceramics offer the advantage of very little friction, and some new ceramic parts are on the market.
Metal on metal: Metal-on-metal joints had been tried before, but they wore out, too. The metal particles they generated often proved to be more harmful than the plastic ones.
As with plastics and ceramics, manufacturing has improved, and a Texas company, Sulzer Orthopedics Inc., recently won the okay from the U.S. Food and Drug Administration to market a metal-to-metal hip joint. It uses a metal socket instead of a polyethylene one.
The joint was designed by Sulzer's Swiss parent company, and it's been used successfully in Europe for a decade, a spokesperson said. Another company also plans to market metal-to-metal hip joints in the United States, and Sulzer is awaiting FDA approval of an all-metal knee joint as well.
Sulzer is marketing the joint for use in younger, more active patients. The firm is so confident it will work, it's offering a lifetime guarantee.
Some doctors also advocate partial knee replacements, which they contend are less invasive and do just as good a job for some patients. One of them is Dr. John P. Barrett, of the Florida Knee and Orthopedic Centers, who has been doing partial knee replacements for the past 15 months.
He still does full joint replacements, too, but says he the partials appear to be working well. And, he says it's relatively easy to go from the partial to a total replacement if the rest of the knee fails.
A partial replacement also requires a shorter hospital stay and much less recovery time, but some doctors question its long-term effectiveness.
Doctors offer a caveat for new materials and new devices as well: In the United States, at least, most have been tested largely on machines, not people. How well they work -- or fail -- won't be evident until they're used in a large numbers of patients for at least 10 years. And because the current prosthetics work well, it's not worth taking too many risks.
"It's exciting to present a patient with new technology, and everyone wants to be able to offer the newest," Warren said. "But it's certainly comforting to be able to present them with technology that 20, 25, 30 years of proven follow-up results."
Total hip replacement: The surgeon cuts into the hip and dislocates the natural joint, being careful not to damage the ligaments or muscles that operate the hip and keep it stable.
Cartilage, bone spurs and other material are reamed from the socket, down to the clean bone of the pelvis. A tight-fitting, plastic-lined metal cup is placed into the joint socket. Some must be secured with screws or cement.
The joint ball at the end of the leg bone, or femur, is cut off. A metal ball on a stem, which looks much like a trailer hitch atop a large golf tee, is implanted into the femur. The ball is snapped into the joint.
The typical hospital stay is three to four days. Recovery includes physical therapy to strengthen the muscles around the joint.
Depending upon use, weight and the quality of the joint materials, patients typically can count on at least 10 to 12 years of wear. Some new surfaces may last 25.
Knee replacement: The surgeon makes a 10- to 12-inch incision and removes the kneecap. The femur and the shin bone, or tibia, are trimmed to make way for the hardware.
A thick plastic cap is embedded into the top of the tibia. A metal cap is embedded into the bottom of the femur, and the back of the kneecap is coated in plastic.
Ligaments and muscles hold the three pieces together, forming the joint. The hospital stay is usually three to four days. Recovery requires intensive physical therapy.
Depending on use, patients can count on 10 to 12 years of use.
Partial knee replacement: Also called partial knee resurfacing. The surgeon caps only one of the three compartments of the knee joint, rather than all three. That stops the grating in that area. Partial replacements are most effective for people who have arthritis on just one side of their knee.
In the past, they would last only about 5 years. But advocates say new materials and techniques have made the partial replacements more durable.
The hospital stay is usually one night. Recovery does not typically require intensive physical therapy.