How Long Does a Knee Replacement Last on Average?
For most people, a total knee replacement is a "one-and-done" procedure. According to large studies and registries (which track hundreds of thousands of patients):
- 82% last 25 years
- 90% last 20 years
- 93% last 15 years
In the past, doctors often told patients that a knee replacement would last 10 to 15 years. That information is now outdated. With improvements in materials (like highly durable plastics and stronger metals) and more precise surgical techniques, implants are lasting longer than ever.
What does "lasting" actually mean?
When surgeons talk about an implant "lasting," they usually mean survivorship. This means the implant is still in place and functioning well enough that it hasn't needed to be removed or replaced (a procedure called "revision knee replacement").
It does not mean the knee feels exactly like it did at age 20. A well-functioning replacement should be painless and stable, but it might still have limitations in how far it can bend, or it might make a little clicking sound now and then. That is considered a success.
What factors affect how long a knee replacement lasts?
While the averages are excellent, nobody is "average."
How long your specific knee replacement lasts depends on a mix of three things: you, the surgery, and your lifestyle.
Age at the time of surgery
A survival analysis of 54,000 knee replacements found:
- Older patients (70+) have a 5% chance of needing revision surgery (no difference between genders)
- Younger patients (under 55): Have a 35% chance of needing revision surgery (woman have a 15% lower chance than men)
For older individuals, their implants last longer partly because they are less active than younger people, putting less stress on the joint.
However, this doesn't mean young people shouldn't have surgery. It just means they need to have a realistic conversation with their surgeon about the possibility of a second surgery (revision) down the road.
Activity level and daily use
Your new knee is a mechanical device. The more you use it, and the harder you use it, the faster it can wear out.
- High-impact activities: Running, jumping, basketball, and heavy manual labour place massive force on the plastic spacer between the metal parts. This can cause it to wear down faster or loosen from the bone.
- Low-impact activities: Cycling, swimming, walking, golf, and doubles tennis are excellent. They keep you strong and healthy without hammering the joint.
Body weight and overall health
More weight correlates to higher chance of revision surgery.
Every step you take puts force through your knee equal to 3–4 times your body weight. If you gain weight, that force multiplies. keeping a healthy weight is one of the single best things you can do to extend the lifespan of your implant.
Chronic conditions like diabetes can also affect how well the bone bonds to the implant, which is crucial for long-term stability.
Surgical technique and implant alignment
A knee replacement is a game of millimeters. If the implant is put in slightly crooked, it can wear unevenly—like a car tire that isn't aligned.
- Surgeon experience matters: Surgeons who do many knee replacements tend to have better long-term results.
- Technology: Some surgeons use robotic assistance or computer navigation to help achieve precise alignment, though excellent results are also achieved with traditional methods.
Signs a knee replacement may be wearing out
The plastic insert in your knee wears down very, very slowly—like tire tread. You won't notice it happening day-to-day.
However, if the implant loosens or the plastic wears through, you might notice:
- New pain: especially pain that happens when you start moving or pain that feels "deep" in the bone.
- Instability: A feeling that your knee is giving way, sliding, or is wobbly.
- Swelling: New swelling that doesn't go away with rest.
- Change in shape: Your leg looking more bowed or knock-kneed than before.
If you have these symptoms, don't panic—but do get it checked. A simple X-ray can often show if there is an issue.
What happens if a knee replacement fails?
If a knee replacement wears out or loosens, it means you may need a revision knee replacement.
What is revision knee surgery?
Revision surgery involves removing the old implant (or just the worn-out plastic part) and putting in a new one.
- It is a longer and more complex surgery than the first time.
- The surgeon may need to use specialized implants with longer stems to anchor them firmly into the bone.
When revision surgery is most common
Most revisions happen for two reasons:
- Early (first 2 years): Usually due to infection or instability.
- Late (15–25+ years): Usually due to normal wear and tear or loosening.
The good news? Most patients don't need a revision.
Does waiting longer for knee replacement surgery affect longevity?
This is a common worry for Canadians stuck on long waitlists. Does waiting hurt my chances of a good result?
Waiting a few months is usually fine. But waiting years can make the surgery harder and the recovery slower.
- Muscle weakness: If you stop moving because of pain, your muscles wither away. Weak muscles make it harder to rehabilitate a new knee.
- Stiffness: If your knee becomes permanently stiff (contracture) before surgery, it is harder to get full motion back afterwards.
- Bone quality: Inactivity can weaken your bones, making it harder for the surgeon to get a solid fixation for the implant.
So, while waiting doesn't necessarily make the implant last less time, it can definitely affect how well you function with it.
Read more: The Dangers of Delaying Knee Replacement Surgery
Exploring knee surgery options in Canada
If you are waiting for knee surgery, and are concerned about a long wait time, then you should know you have options.
While the public system provides excellent care, the timelines can be long for major orthopedic surgeries. Thousands of Canadians choose to access private knee replacement surgery at accredited private surgical centres within Canada.
These clinics operate fully legally and follow the same strict safety standards as public hospitals. The main difference is that you pay for the procedure out-of-pocket to access surgery in weeks rather than months or years.
Surgency is a platform that helps you compare these providers, understand the costs, and see the timelines—all in one place. We don't provide the surgery; we provide the clarity you need to make a decision.
Click here to explore your options.
FAQs
What happens 20 years after a knee replacement?
For most people? Nothing. They are still walking and enjoying life. If the implant does wear out, you might start to feel some pain or instability, which is a sign to see your surgeon about a possible revision. 90% of knee replacements last 20 years or longer.
How do you know when your knee replacement is wearing out?
You often won't know until it starts to hurt. That is why many surgeons recommend getting an X-ray every few years, even if you feel fine. It allows them to catch wear early before it causes damage to the bone.
How many times can knee replacement be done?
Technically, a knee can be replaced more than once (a revision of a revision), but each time the surgery gets harder and the results are a bit less predictable. The goal is always to have the first one last as long as possible.
What can you never do after knee replacement?
Most surgeons advise avoiding high-impact sports like jogging on pavement, singles tennis, or contact sports (hockey, football). These activities put too much sudden force on the implant and risk loosening it prematurely.
Read on: Knee Replacement Exercises to Avoid
Conclusion
A knee replacement is a long-term investment in your quality of life. For the vast majority of patients, that investment pays off for 20 years or more.
While no surgery comes with a lifetime guarantee, modern implants are incredibly durable. By staying active with low-impact exercise, maintaining a healthy weight, and following your surgeon’s advice, you can help your new knee go the distance.
If you are tired of waiting and want to understand your options for faster access to surgery, Surgency can help you compare private surgical providers.
- Learn about private options: Private Knee Replacement
- Understand the costs:
