February 10, 2012 — CHICAGO (AP) — Nearly 1 in 20 Americans older than 50 have artificial knees, or more than 4 million people, according to the first national estimate showing how common these replacement joints have become in an aging population.

Doctors know the number of knee replacement operations has surged in the past decade, especially in baby boomers. But until now, there was no good fix on the total number of people living with them. The estimate is important because it shows that a big segment of the population might need future knee-related care, said Dr. Daniel Berry, president of the American Academy of Orthopedic Surgeons and chairman of orthopedic surgery at the Mayo Clinic in Rochester, Minn. He was not involved in the research.

People with knee replacements sometimes develop knee infections or scar tissue that require additional treatment. But also, even artificial knees wear out, so as the operations are increasingly done on younger people, many will live long enough to almost certainly need a second or even third knee replacement.

The new estimate comes in an analysis being presented Friday at the academy's annual meeting in San Francisco. "These data are sobering because we didn't know what an army of people we've created over the last decade," said Elena Losina, lead author of the analysis and co-director of the Orthopedics and Arthritis Center for Outcomes Research at Harvard's Brigham and Women's Hospital. "The numbers will only increase, based on current trends."


Replacement joints can greatly improve quality of life for people with worn-out knees, but they're not risk-free and it's a major operation that people should not take lightly, she said. Modern knee replacements in the United States date back to the 1970s. Since then, advances in materials and techniques, including imaging scans to create better-fitting joints, have made the implants more durable and lifelike, surgeons say.

Losina and colleagues came up with their estimate by analyzing national data on the number of knee replacements done from 1998-2009, U.S. census data, death statistics and national health surveys. For example, in 2009, more than 600,000 knee replacement operations were done nationwide. The study estimate includes people who had knee replacement operations that year and in previous years who are still living.

Overall, 4.5 million Americans are living with artificial knees. That includes an estimated 500,000 who have had at least two replacement operations on the same knee. Knee replacements are most common in people older than 80 — 1 in 10 people in this age range have them, the study found. Though they're less prevalent in people younger than that, there are still more than half a million Americans in their 50s with the artificial joints, and based on current trends, operations in that age group are expected to increase.

According to the federal Agency for Healthcare Research and Quality, knee replacements tripled in people ages 45 to 64 between 1997 and 2009. Doctors think two trends have contributed to that increase: the nation's obesity epidemic and amateur athletes who don't adjust workouts to spare aging or even injured joints. Both can lead to or worsen arthritis, the main reason for replacing knees.

Donna Brent, 63, is in the latter category. The Deerfield, Ill., administrative assistant says decades of racket ball, tennis, softball and other sports took a toll on her knees, but she got used to living with the pain, even when she became bowlegged and developed a limp. When pain "started getting in the way of some of my sports," she gave in to her doctor's advice and had the operation last June on her right knee. She said she feels better than ever, is back to exercising and plans to resume tennis and softball when the weather warms up.

During knee replacement operations, surgeons slice off a small portion of the worn-out surface on the ends of both leg bones that meet at the knee, then implant an artificial joint usually made of plastic or metal. Typical operations last about two hours, require a few days in the hospital, and cost roughly $40,000.

Artificial knees generally last 15 to 20 years. While some are promoted as lasting 30 years, these estimates are generally based on use among older people more sedentary than baby boomers who expect new knees to let them be as active as they were before surgery. Sometimes that's possible, though doctors often discourage knee replacement patients from engaging in high-impact sports including jogging.

The National Institute of Arthritis, Musculoskeletal and Skin Diseases paid for the study.

 

What?! No "high impact" activities after new knees?? Isn't that the entire point?

I need a new knee bushing. Wonder if Hyperflex makes a bolt on kit?

 

Somehow Shorts I fail to see you sitting still long enough to recover from the procedure.

 

lol That's actually very true. You shoulda seen what I did when I was recovering from my broken neck. If the Drs knew they would have strangled me.

I will be an ornery 70 year old. I cannot wait

 

With an attitude like that, you may not have to.

 

I haven't seen one yet with a grease zerk on it. Doesn't make sense to me.

 

I've been rehabbing a shoulder after surgery and have seen my share of knee replacements. Like all surgery it involves risks and everyone heals differently. Universally though,everyone I've met in PT has expressed satisfaction with their replacements and a higher quality of life. My neighbor across the street had a hip replacement right before Christmas and is doing fine. She was gulping Vicodin like candy before.

 

Yeah, Dad's glad to have his knee finally done. He just had his hip done too and he's a brand new man. No pain and he's feeling really really good with PT. He's dropped some weight and isn't taking all those meds for BP and all that.

 

Wife just got something injected into her left knee to relieve the pain and swelling. Cartilage is just about gone. Eventually the knee will have to be changed out.

On a side note, she applied for medicare yesterday. She has spent her entire life raising children at home, and thus has to go on my social security to get it. When asked when she married me, she said 1970. She was then asked if she had a previous marriage of 10 years or more.

Actually the interview went very well. He just had to read all the questions. We all laughed about it. If the paperwork goes as well as the interview, we're in good shape.

 

Had Arthroscopic done 2 years ago.

Can't say it was terrible, but the Oxy they shoved down my throat took care of that. When I left the hospital, I felt fine. The next day was painful, but I made a full recovery, within a few days. Had to baby it, and took 6 months to be able to kneel on it again.

Doc said.... next time..... could be a replacement. Told to lay off the Basketball, running, jumping and all other impact activities.... and maybe I could get it to last longer.

So far, I can tell when the storm fronts are moving in, as the discomfort settles in and it feels uncomfortable... with minimal cartilage left. Oh well...

At least it looked cool in there.... The tear was circled in Red.

 

It looks like a butt crack!

 

Coming from a guy with almost 43,000 votes for him being the "Less Ugly" dude, I guess you have a point.



I always wanted to look like Robert Plant, myself, but I wound up short in the looks dept..... I'm more Robert Redford, or Brad Armpit

 

NJTman, cool photos. They really came out pretty clear. My freshman yr of h.s. a friend and teammate blew out her ACL and had to have surgery to repair it. She had it video taped and when she came home we had a video watching party lol

 

Stayed home today because of my right knee. It has been over 2 years since my surgery and it's only getting worse. People that want to do sports and such after a knee replacement are crazy. I just want to be able to get around with no pain and ride my horses. Said to say a knee replacement is in my near future.

 

Hey, I already lost a limb. I'm not going out with only one of each

Forever young!

But in all seriousness, hope you and you knee feel better, whatever the course may be.