WebMD—November 27, 2007
If your mother or grandmother had a knee or hip replacement, the odds are good she was in her late 60s or 70s when she opted for the surgery, and it was a "last resort" decision -- either get a new knee or start using a cane or a wheelchair.
That's not today's joint replacement surgery.
"It used to be about doing the things you needed to do -- literally, being able to walk," says David Mayman, M.D., clinical co-director of the computer-assisted surgery center at New York's Hospital for Special Surgery. The hospital is world-renowned for orthopedic surgery and pioneered the first total knee replacement.
"Now, patients are coming to see us saying, 'I can't do the things I want to do. I can't play golf or tennis anymore.' We're seeing more and more patients in their 50s and even some in their 40s," he tells WebMD. "Where these people used to wait and try to hold out another year or two or five, now they just want to get it done and get on with their lives."
Arthritis is the leading cause of joint replacements. And because women have higher rates of arthritis than men, some 60% of joint replacement surgeries are performed on women.
The demand from women has even sparked a whole new industry in "gender-specific joint replacement," with several companies offering knees that purport to be designed for a woman's anatomy.
Whether a "woman's knee" is markedly better than a knee that works for men or women is debatable, says Mayman. "There are some anatomical differences between men's and women's joints, but geometrically, they're very similar," he says. "I don't know that the literature suggests any better outcomes with gender-specific replacements. But these devices do highlight the fact that there are different types of joint replacements, and anatomically, you need one that fits your bone."
Before you can start shopping for a new knee or hip, though, you should be thinking about whether joint replacement surgery is right for you. Here are three questions to ask yourself before plunging into surgery:
"When your lifestyle starts changing because of your hip or your knee, and there are things you enjoy doing that you can no longer do, that's the time to start thinking about the surgery," says Mayman.
If you aren't 100% invested in your own recovery, you may not be a good candidate for surgery. Joint replacement surgery is a major undertaking. Especially with knees, you can't just sit back and wait for your body to heal and become its old self again.
After surgery, you'll likely be in the hospital for three to four days, and then you'll be given a program of rehabilitation and physical therapy for at least six weeks.
"A large part of how well a patient does depends on how focused they are around rehabilitation," says Mayman. "Especially with knees, you have to work very hard on getting your range of motion back. If you don't do that, scar tissue can form in the knee and you get limited range of motion. With a hip replacement, what you really have to do is get up and walk, but with knees, it requires diligent attention to specific exercises. The harder you work in physical therapy, the more range of motion you'll get."
Newly designed knee replacements can help you with range of motion. Some artificial knees that have entered the market in the last five years are designed to allow the knee to flex more. But in order for your new knee to flex and move, you have to build strength in the soft tissues around it. Your recovery is up to you.
Patients who are willing to work toward rehabilitation can expect excellent recovery and long life for their new joints.
"With the current generation of joint replacements, 90% or greater last 20 years or longer, and 30 years out, it's about 70%," says Mayman. "The range of longevity depends on how active people are. If you're running and jumping on the new joint, it'll wear out a little sooner. It's just like putting new tires on a car. If you drive it to the grocery store, they'll last longer, but if you're drag racing, they'll wear out faster."
Once you've settled on joint replacement surgery, what should you do next?
First, find a specialized surgeon. An orthopedic surgeon who specializes in joint replacement will have much better outcomes than a general orthopedic surgeon.
Studies repeatedly have found that the more of a specific operation a surgeon performs, the better the outcome. So a doctor who's done 100 knee replacements in the past year is probably a better choice than someone who's done five.
Second, know your options. For example, many people think it might be a better option to get a "partial" knee replacement rather than a total knee replacement. It sounds less invasive and easier, right? While that's true, partial knee replacements have their down sides.
"It's a smaller operation and the recovery time is a little faster, and the knee feels more like a normal knee," says Mayman. "But the downside is a higher failure rate." Mayman says his hospital sees a 10% failure rate for partial knee replacements after 10 years. It takes 20 years for total knee replacements to hit a 10% failure.
And what about "hip resurfacing?" That, too, sounds like it might be easier than getting a whole hip replaced. But in this case, the opposite is true. "It's actually a bigger incision with longer recovery time," says Mayman. "It does save bone in the femur, but there are a number of negatives for women."
First, women -- especially those with osteoporosis -- face a higher risk of femoral neck fracture after hip resurfacing. Also, since the surgery involves a metal-on-metal-bearing surface, elevated levels of cobalt and chromium can be found in the blood after surgery. No ill effects have been shown due to these metals so far, but most surgeons won't do hip resurfacing in women of childbearing age since the metals can cross the placenta.
You can also discuss some of the newer joint replacement options with your surgeon, such as ceramic and crosslinked polyethylene bearings, which may last longer than previous generation joints, as well as new knee designs that "should act more like a normal knee," says Mayman.
Some doctors, including Mayman, now use computer navigation to aid joint replacement surgery. It doesn't change the implant itself, or the operation, but it's a more precise guide to putting the joint in place.
"If you use standardized guides, you're within the ideal alignment range about 80% of the time. With computerized guides, it's about 95% of the time," he says. "That should benefit the patient in the long term, because we know that outcomes are better if the joints are within that ideal alignment."
Here's one last tip for women considering joint replacement surgery: Get screened for osteoporosis.
"If you have hip or knee pain and arthritis that's got you thinking about surgery, it's a good time to be screening for osteoporosis," says Mayman. "It's something all women this age should be thinking about, and if you're replacing a joint, it's important to be thinking about protecting the bone that you have."
To read the full article, go to WebMD.com.
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