How Long Does a Knee Replacement Last? Longevity and Registry Data
Key takeaways
- A modern knee replacement typically lasts 15 to 20 years or more.
- Around 90 to 95% of knee replacements are still working at 10 years, according to National Joint Registry and AAOS data.
- Younger, heavier, and more active patients tend to wear an implant out sooner, so the longevity question matters most for them.
- When an implant does wear out or loosen, it can usually be redone with a revision knee replacement.
- Looking after your weight, staying active without high-impact pounding, and attending follow-up all help your new knee last.
By Margaret Doyle | Medically reviewed by Mr Paul Henderson, FRCS (Tr&Orth)
Updated April 28, 2026 · 3 min read
A modern knee replacement typically lasts 15 to 20 years or more, and registry data shows around 90 to 95% are still in place at 10 years. How long yours lasts depends on your age, weight, activity level, and the type of implant, but for most people a knee replacement is a once-in-a-lifetime or twice-in-a-lifetime operation rather than something that fails quickly1.
When I was deciding whether to go ahead, “how long will it last?” was the question that kept me awake. Nobody wants major surgery only to face it again in a few years. So here are the real numbers, checked by a consultant orthopaedic surgeon, and the honest factors that change them. If you are still weighing up the operation itself, start with our guide to knee replacement surgery.
How long does a knee replacement last?
A knee replacement typically lasts 15 to 20 years or more. The implant is a hard-wearing combination of metal and plastic, and the part most likely to wear over time is the plastic spacer between the components. Modern materials and surgical technique have steadily pushed that lifespan up, which is why current figures are better than the ones your parents may remember2.
That said, a replacement is a mechanical part inside a living joint, so it does not last forever in everyone. Thinking in ranges rather than a single guaranteed number is the honest way to plan.
What the registry survival data shows
Around 90 to 95% of knee replacements are still in place at 10 years, according to the National Joint Registry and the American Academy of Orthopaedic Surgeons. The registry tracks hundreds of thousands of operations, which makes it a far more reliable guide than any single surgeon’s experience1.
This covers both total knee replacements (which resurface all three compartments of the knee with metal and plastic components) and partial replacements. It is the figure I would hold on to: at the 10-year mark, the large majority of new knees are still doing their job.
What makes a knee replacement last longer or shorter?
Several things shift your personal odds away from the average:
- Age: the most common age for surgery is 60 to 80, and older patients tend to place fewer demands on the implant, so it lasts longer.
- Weight: extra body weight loads the joint with every step and speeds up wear.
- Activity: high-impact activity (running, jumping, heavy manual work) wears the plastic faster than walking, cycling, and swimming.
- Implant type and fixation: your surgeon chooses components and whether to cement them based on your bone and activity level.
- Complications: infection (which affects about 1 to 2 in 100) or injury can shorten an implant’s life.
I was in my early sixties and not especially sporty, which my surgeon said put me in a good position for the implant to go the distance. A 45-year-old marathon runner is a different conversation, and an honest surgeon will say so.
What happens when a knee replacement wears out?
When an implant eventually loosens, wears, or becomes infected, it can usually be redone in a revision knee replacement. Revision is a bigger and more technical operation than the first one, but it can buy many more years of use. Because around 90 to 95% of first replacements are still working at 10 years, most people do not face revision within that window3. Read more in revision knee replacement, which explains when and why a replacement is redone.
How to help your knee replacement last
You cannot control your age, but you can influence the rest. Keeping to a healthy weight, staying active with low-impact exercise rather than high-impact pounding, doing your physiotherapy so the joint stays strong and stable, and attending your follow-up appointments all give the implant its best chance. Most people stay in hospital just 1 to 3 days and are walking with aids the same day, but the long game is what protects the implant over the years4.
If longevity is central to your decision, it is worth reading alongside knee replacement success rates, which covers satisfaction and the honest reality that about 1 in 5 people feel their knee is never quite “normal”, and our overview of knee replacement risks and complications.
References
- How long does a knee replacement last?, National Joint Registry. ↩
- Total Knee Replacement (OrthoInfo), American Academy of Orthopaedic Surgeons. ↩
- Knee replacement surgery, Versus Arthritis. ↩
- Knee replacement, NHS. ↩
Common questions
How long does a knee replacement last on average?
A modern knee replacement typically lasts 15 to 20 years or more. Registry and AAOS data show around 90 to 95% are still in place at 10 years, and a large share last well beyond that. Your age, weight, activity level, and implant type all affect how long yours will last.
What percentage of knee replacements are still working at 10 years?
Around 90 to 95% of knee replacements are still in place at 10 years, according to the National Joint Registry and the American Academy of Orthopaedic Surgeons. That figure covers both total and partial knee replacements across large numbers of patients.
What makes a knee replacement wear out faster?
Being younger and more active, carrying extra weight, and doing high-impact activity all add wear to the plastic and can loosen the implant sooner. Infection and injury can also shorten the life of a replacement. This is why surgeons weigh implant lifespan carefully when advising younger patients.
Can a knee replacement be done again?
Yes. When an implant wears out, loosens, or becomes infected, it can usually be redone in a revision knee replacement. Revision is a bigger operation than the first one, but it can give many more years of use. Around 90 to 95% of first-time replacements are still working at 10 years, so most people never need it within that window.
Does a partial knee replacement last as long as a total?
A partial (unicompartmental) knee replacement resurfaces only the one damaged compartment and keeps healthy bone and ligaments. It tends to feel more natural and recover faster, but it carries a somewhat higher chance of needing revision over time. Your surgeon will explain the trade-off for your knee.
Will my knee replacement last the rest of my life?
For many older patients it does. If you have surgery in your late sixties or seventies and the implant lasts 15 to 20+ years, it may well see you through. Younger patients are more likely to outlive a first implant and need a revision later, which is a normal part of planning.
Written by Margaret Doyle. Medically reviewed by Mr Paul Henderson, FRCS (Tr&Orth).
Our guides are written from personal experience and reviewed by a qualified clinician for accuracy. Read our editorial policy.