Direct answer
Most total knee replacements last 20 years or more, and a large share last 25 years or longer. The main figures:
- 25 years: about 82% of total knee replacements still in place, pooled from 14 national registries (The Lancet, 2019).
- 20 years: about 90% still in place in a UK cohort of 54,276 knees.
- 10 years in Canada: about 3 to 4 in every 100 total knee replacements had been revised, with the risk highest in people under 55 (CJRR, 2024–2025).
- Partial knee replacement: about 70% still in place at 25 years, with roughly double the revision risk of a total replacement in Canadian data.
- What shortens implant life: younger age at surgery, higher body weight, high-impact activity, poor component alignment, and infection.
This guide is for people deciding whether to have a knee replacement now, people who already have one, and the family members helping them plan. It covers what the registries show, what changes an implant’s lifespan, how partial and total replacements compare, and the signs that mean a surgeon should look at your knee.
Every figure below comes from a national joint registry, a public health body, or a peer-reviewed study linked in the text. Your surgeon reads these numbers against your age, weight, bone quality and goals.
How long does a total knee replacement last?
The strongest answer comes from a 2019 systematic review and meta-analysis in The Lancet. Researchers pooled national registry reports covering 299,291 total knee replacements from 14 registries, plus case series with at least 15 years of follow-up. The pooled registry estimate was that 82.3% of total knee replacements were still in place at 25 years (95% confidence interval 81.3–83.2).
A 2017 population-based study, also in The Lancet, followed 54,276 total knee replacements in the UK for up to 20 years. Implant survival was 96.1% at 10 years and 89.7% at 20 years. Public health bodies summarize the same evidence in plainer terms: the American Academy of Orthopaedic Surgeons (AAOS) says more than 90% of modern total knee replacements are still functioning well 15 years after surgery, and the NHS says most knee replacements last about 25 years.
| Time since surgery | Total knee replacements still in place | Source |
|---|---|---|
| 10 years | 96.1% (UK cohort of 54,276 knees); about 96–97% in Canada (CJRR cumulative revision 3.3–3.9%) | Bayliss et al., 2017; CIHI CJRR, 2024–2025 |
| 15 years | More than 90% | AAOS OrthoInfo |
| 20 years | 89.7% (UK cohort) | Bayliss et al., 2017 |
| 25 years | 82.3% (pooled from 14 national registries) | Evans et al., The Lancet, 2019 |
Two things to keep in mind when you read these numbers. First, “still in place” means the implant has not been revised; it does not mean every knee feels perfect. Second, the 25-year figures describe implants put in during the 1990s. Implant design, surgical technique and infection control have all changed since, and the Canadian registry notes that robotic-assisted procedures are still a small share of the total, so long-term data on today’s implants will take time to mature.
How long do knee replacements last in Canada?
The Canadian Joint Replacement Registry (CJRR), run by the Canadian Institute for Health Information, tracks every hip and knee replacement in participating provinces. Surgeons performed 95,896 knee replacements in Canada in 2024–2025, 99.6% of them for osteoarthritis. The most common age group was 65 to 74.
The registry’s revision curves, built from surgeries performed between 2012 and 2025, show a cumulative revision risk of 3.28% at 10 years for total knee replacements with patellar resurfacing and 3.87% without. In plain terms, about 96 to 97 of every 100 Canadian total knee replacements were still in place a decade on. Age at surgery changes those odds considerably:
| Age at surgery | Revised within 10 years (men) | Revised within 10 years (women) |
|---|---|---|
| Under 55 | 8.9% | 6.7% |
| 55–64 | 5.0% | 4.0% |
| 65–74 | 3.4% | 2.6% |
| 75 and older | 2.5% | 2.0% |
Cumulative percentage revision for primary total knee replacement for osteoarthritis, CJRR 2012–2013 to 2024–2025. Figures rounded to one decimal place.
The registry also records why Canadian knees are revised. In 2024–2025 the leading reason was infection (34.1% of knee revisions), followed by aseptic loosening (15.0%), instability (11.5%), pain and other complications (8.6%), and fracture around the implant (4.4%). Bearing wear, the slow erosion of the plastic insert that people most often picture when they think of an implant “wearing out”, accounted for 2.3%.
What shortens the life of a knee replacement?
Age at surgery
Younger patients put more years and more load on an implant, so they are more likely to need a revision in their lifetime. The UK study above estimated the lifetime risk of revision at about 5% for people who had surgery after age 70, rising to as high as 35% for men who had surgery in their early 50s, with women in the same age group about 15 percentage points lower. For people under 60, the median time to revision was 4.4 years, which points to early problems such as infection and instability rather than slow wear. The Canadian table above shows the same pattern.
Body weight
A meta-analysis of 20 studies in the Journal of Bone and Joint Surgery found that obese patients (body mass index of 30 or more) had higher odds of any infection (odds ratio 1.90), deep infection needing surgery (odds ratio 2.38) and revision for any reason (odds ratio 1.30) after total knee replacement. The AAOS lists excess weight as a factor that can speed up wear and loosening. There are no absolute weight limits for surgery, and your surgeon weighs this risk against the benefit of treating your arthritis.
Activity
The AAOS notes that every total knee replacement begins to wear in its plastic spacer, and that heavy use speeds this up. Most surgeons advise against running, jogging, jumping and other high-impact sport for life, and encourage unlimited walking, swimming, golf, cycling, light hiking and ballroom dancing. Pathway’s knee replacement procedure page gives the same guidance.
Alignment
How the components sit on the bone matters. In a review of 6,070 knees, the failure rate (revision for any reason other than infection) was 0.2% when both the tibial and femoral components were in neutral alignment and 8.7% in the worst-aligned combination. Higher body mass index raised the failure rate at every alignment. Pathway’s surgeons use ROSA and VELYS robotic systems to plan and check component position during surgery; the robot assists the surgeon and does not operate on its own.
Infection
Infection is the leading cause of knee revision in Canada. The AAOS puts serious complications, including joint infection, at fewer than 2% of patients, and explains that bacteria from dental work, urinary infections or skin infections can travel through the bloodstream and settle on the implant years after surgery. Prevention runs for the life of the implant: finish major dental work before surgery, tell your dentist you have a knee replacement, treat skin and urinary infections promptly, and ask your surgeon whether you need antibiotics before dental procedures.
What helps a knee replacement last longer?
- Low-impact activity. The AAOS says lower-impact fitness such as golf, cycling and pickleball will help increase the longevity of your knee, and advises avoiding jumping, jogging and skiing.
- Keep doing your exercises. The AAOS advises continuing the exercises your physiotherapist prescribed for at least two months after surgery. Strong quadriceps and hamstrings protect the joint.
- Watch your weight. Both the AAOS and the studies above link extra load to faster wear, loosening and infection.
- Protect the implant from infection. Keep up with dental care, treat infections early, and ask about antibiotics before dental work.
- Attend follow-up. Your surgeon checks the implant on X-ray and asks about new pain or swelling.
- Report changes early. A new symptom is easier to treat before bone loss or deep infection sets in.
Do partial knee replacements last as long?
A partial (unicompartmental) knee replacement resurfaces one compartment of the knee and keeps the ligaments and the healthy cartilage. On average, it is revised sooner than a total replacement. The Lancet meta-analysis estimated 25-year survival of 69.8% for partial replacements, from four registries covering 7,714 implants, against 82.3% for total replacements. In the Canadian registry, a medial partial knee replacement carried about 2.2 times the revision risk of a total knee replacement with patellar resurfacing, after adjusting for age and sex.
That is one side of the ledger. A 2019 systematic review in the BMJ of 60 studies found that partial replacement meant hospital stays about 1.2 to 1.7 days shorter, better function scores, and, in registry and large-database studies, lower rates of death, blood clots and major cardiac events than total replacement. Revision at five years was higher after partial replacement in every group of studies. A worn partial replacement can be converted to a total replacement.
Pathway’s guide to partial vs. total knee replacement covers who qualifies for a partial replacement. Your surgeon decides based on how many compartments are worn, whether your ACL is intact, and how your knee is aligned.
What are the signs a knee replacement is failing?
The AAOS lists the symptoms that bring people back to their surgeon:
- Pain that is new, or increasing after a period of comfort, especially pain with weight-bearing or at rest.
- Swelling that keeps coming back.
- Stiffness or a loss of bend that you did not have before.
- Instability, a sense that the knee is giving way.
- Difficulty with everyday activities that used to be comfortable.
- Signs of infection: stiffness, pain and drainage from the old incision, sometimes with fever or chills.
Your surgeon starts with X-rays to look for loosening or a change in component position. Blood tests and a joint aspiration, in which fluid is drawn from the knee with a needle and sent for analysis, check for infection. A bone scan, CT or MRI is used in some cases to confirm loosening or assess the bone. Wear particles from the plastic insert can trigger an immune response that thins the surrounding bone, a process called osteolysis, which your surgeon looks for on follow-up X-rays.
What happens if a knee replacement wears out?
The answer is revision surgery. The surgeon removes some or all of the original components and fits new ones, often with longer, thicker stems that anchor deeper in the bone. Bone that has been lost is rebuilt with metal augments, blocks or, less often, bone graft. For an infected knee, the AAOS describes two approaches: cleaning the joint and keeping the implant, or a two-stage operation in which the implant comes out, an antibiotic spacer goes in, and a new implant is placed after a course of intravenous antibiotics.
Revision is a longer and more complex operation than a first replacement, with a higher risk of wound problems, stiffness, infection, bleeding and fracture. The CJRR reports that patients admitted for revision surgery stayed in hospital more than twice as long as patients having a primary replacement (9.3 days versus 3.6). The AAOS reports that most patients still have good long-term outcomes, including relief from pain and improved stability, although some keep some pain or stiffness.
When to call your care team
These signs apply whether your knee replacement is six weeks old or sixteen years old.
Call 911 for sudden shortness of breath, chest pain, or chest pain with coughing. These can signal a blood clot in the lungs.
Call your surgeon or care team the same day for:
- Possible infection: fever, chills, increasing redness, warmth, tenderness or swelling around the knee, drainage from the incision, or knee pain that rises both at rest and with activity.
- Possible blood clot: calf pain, calf tenderness or redness, or new swelling of the calf, ankle or foot.
- Possible implant problem: a sudden change in how the knee feels after a fall, a knee that gives way, or a new inability to bear weight.
These signs reflect guidance from the AAOS and the NHS. Your care team may give you a different fever threshold or contact plan; follow theirs.
Quick answers
How long does a knee replacement last on average?
Pooled data from 14 national joint registries, published in The Lancet in 2019, estimated that about 82% of total knee replacements were still in place 25 years after surgery. The AAOS says more than 90% of modern total knee replacements are still functioning well at 15 years, and the NHS says most last about 25 years.
Can a knee replacement last 30 years?
Some do. Registry estimates put 25-year survival of total knee replacements at about 82%, and many of those implants keep working beyond that point. Published registry data beyond 25 years is limited, so no one can promise a specific number for an individual knee. Age at surgery, weight, activity and infection all shift the odds.
Do partial knee replacements last as long as total knee replacements?
On average, no. The same Lancet analysis estimated 25-year survival of about 70% for partial (unicompartmental) knee replacements, compared with about 82% for total knee replacements. Canadian registry data show roughly double the revision risk for a medial partial knee replacement compared with a total knee replacement. Partial replacements offer other advantages, including shorter hospital stays and better function scores in registry comparisons.
What are the signs a knee replacement is failing?
New or increasing pain, swelling that keeps coming back, stiffness, a feeling that the knee is giving way, and growing difficulty with everyday activities. Pain, stiffness and wound drainage can point to infection. Your surgeon investigates with X-rays, blood tests and sometimes a joint aspiration or a bone scan.
Can a knee replacement be redone?
Yes. The operation is called a revision knee replacement. The surgeon removes some or all of the original components and replaces them, often with implants that have longer stems. Revision is a longer and more complex operation than the first replacement, and the AAOS reports that most patients still achieve good long-term pain relief and function.
Questions to ask your surgeon
- Given my age and weight, what is my realistic chance of needing a revision in my lifetime?
- Am I a candidate for a partial replacement, and how would that change the long-term picture?
- Which implant do you plan to use, and how long has that design been in registry data?
- Will you resurface my kneecap, and why?
- How will you check alignment during surgery?
- Which sports should I give up, and which can I keep?
- Do I need antibiotics before dental work, and for how long?
- How often should I have follow-up X-rays once the knee has healed?
If you are planning the surgery itself, Pathway’s guide to knee replacement recovery time walks through the first year week by week. You can also read about Pathway knee surgeon Dr. Sebastian Rodriguez-Elizalde, who has performed more than 5,000 combined robotic knee and hip replacements.
References
- Evans JT, Walker RW, Evans JP, Blom AW, Sayers A, Whitehouse MR. How long does a knee replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up. Lancet. 2019;393(10172):655–663.
- Bayliss LE, Culliford D, Monk AP, Glyn-Jones S, Prieto-Alhambra D, Judge A. The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study. Lancet. 2017;389(10077):1424–1430.
- Canadian Institute for Health Information. Hip and Knee Replacements in Canada: CJRR Annual Report, 2024–2025. Ottawa, ON: CIHI; 2026. Accessed October 21, 2026.
- American Academy of Orthopaedic Surgeons (OrthoInfo). Total Knee Replacement. Accessed October 21, 2026.
- American Academy of Orthopaedic Surgeons (OrthoInfo). Revision Total Knee Replacement. Accessed October 21, 2026.
- American Academy of Orthopaedic Surgeons (OrthoInfo). Activities After Knee Replacement. Accessed October 21, 2026.
- NHS. What is a knee replacement? and Complications of a knee replacement. Accessed October 21, 2026.
- Kerkhoffs GM, Servien E, Dunn W, Dahm D, Bramer JA, Haverkamp D. The influence of obesity on the complication rate and outcome of total knee arthroplasty: a meta-analysis and systematic literature review. J Bone Joint Surg Am. 2012;94(20):1839–1844.
- Ritter MA, Davis KE, Meding JB, Pierson JL, Berend ME, Malinzak RA. The effect of alignment and BMI on failure of total knee replacement. J Bone Joint Surg Am. 2011;93(17):1588–1596.
- Wilson HA, Middleton R, Abram SGF, et al. Patient relevant outcomes of unicompartmental versus total knee replacement: systematic review and meta-analysis. BMJ. 2019;364:l352.
Health information notice: This article provides general information about implant survival and cannot replace individual medical advice. Your surgeon and care team assess your knee, your health and your goals before recommending any procedure.