Questions & Answers · Knee
How long does a knee replacement last?
About 82% of total knee replacements are still in place 25 years after surgery, and more than 90% are still working at 15 years. Those are registry numbers, not marketing. How long yours lasts depends mostly on four things — your activity choices, your body weight, your bone quality, and how precisely the implant was placed — which is the conversation Dr. Paul Chin and Dr. Brian Flowers have with every knee patient at Sterling Ridge Orthopaedics & Sports Medicine in The Woodlands and Spring.
The numbers, from the registries
The best evidence on implant survival comes from national joint registries, which follow every replacement a country performs for decades. Here is what they show:
- 1 year
0.83% revised
The American Joint Replacement Registry, drawing on 3.7 million U.S. cases, reports a 0.83% revision rate one year after total knee replacement (AJRR, 2024). Early revisions are usually infection or instability, not wear.
- 10 years
2.60% revised
The same U.S. registry puts the ten-year revision rate at 2.60% (AJRR, 2024) — more than 97 of every 100 knees still in place a decade later.
- 15 years
More than 90% working
AAOS's patient guide states that more than 90% of knee replacements are still functioning 15 years after surgery (OrthoInfo).
- 25 years
82% total, 70% partial
A Lancet analysis of 299,291 knee replacements across national registries found about 82% of total knees and about 70% of partial knees still in place at 25 years (Evans et al., 2019).
Two caveats the studies themselves make. Registry patients were mostly older adults, so a 50-year-old's knee faces more years and more steps than the average patient in those numbers. And "still in place" means not revised — a knee can be imperfect without being replaced. Still, for most patients in their 60s and 70s, the first knee is very likely the last.
What shortens an implant's life
- Infection — the most serious threat, and the most common reason for early revision. Dental infections, skin infections and uncontrolled diabetes all raise the risk, which is why we take them seriously for life.
- Loosening — the bond between implant and bone can weaken over years, especially with poor bone quality or an implant placed off-plan. Loosening usually shows up as a new, deep ache with weight-bearing.
- Wear — the plastic spacer wears slowly with every step. High-impact repetition (running on pavement, jump-heavy sports) and excess body weight wear it faster than golf, cycling and swimming.
- Falls and fractures — a fall onto a replaced knee can fracture the bone around the implant or damage the kneecap, turning a stable knee into a revision case overnight. Balance training in rehab is implant protection.
What you control
- Precise placement — implants aligned to plan wear more evenly. This is the practical case for robotic assistance: a pooled analysis of 12 randomized trials found robotic surgery produced fewer alignment outliers, though with no proven difference in function or revision so far (Ruangsomboon et al., 2023). Dr. Chin and Dr. Flowers both perform robotic-assisted knee replacement.
- Strong muscles around the joint — rehab isn't a formality; it's armor for your implant. Our in-house therapy team shares a chart with your surgeon.
- Staying active the smart way — motion is good; impact is the tax. Walking, cycling, swimming, golf and doubles tennis are what the implant was designed for.
- Body weight and blood sugar — every added pound multiplies across a few million yearly steps, and the AAOS surgical guideline notes a BMI above 40 raises infection risk and advises an A1c below 6.5 before surgery (AAOS, 2023).
- Treating infections early — tell every doctor and dentist you have a joint replacement, and don't sit on a fever or a red, hot knee.
And if it wears out? When a worn knee needs a revision specialist
Revision surgery replaces a worn, loose or infected implant. It's more complex than a first replacement — old parts have to come out, bone loss has to be rebuilt, and the new implant often needs stems and augments — and it belongs in hands that do it regularly. At Sterling Ridge, that's Dr. Rohan Gheewala, who completed an adult reconstruction fellowship at Baylor College of Medicine and handles primary, complex and revision hip and knee replacement, including second opinions on a replacement that never felt right.
Signs a replaced knee should be re-evaluated: new or deepening pain after years of comfort, a knee that feels unstable or gives way, swelling that returns without a reason, or any fever or redness around the joint. Bring your operative report if you have it; an X-ray and an exam usually tell us whether the knee needs watching, a minor procedure, or a revision.
The other half of a long-lasting joint: the rehab
Implant materials set the ceiling — rehab decides how close you get to it. The knees that reach the 25-year end of the range belong to patients whose muscles learned to protect the new joint. That's why our in-house rehab team works in the same buildings as our surgeons: your therapist and your surgeon share one chart, one hallway, and one plan for making this knee your last one. Sterling Ridge is one of the leading joint replacement practices in the Houston area, with qualified patients having surgery as outpatients at the Sterling Ridge / Woodforest Ambulatory Surgical Center. Our surgeons also hold privileges at several area hospitals, so when your insurance plan or your medical history calls for a hospital setting, surgery is scheduled there instead. Consults are at our offices in The Woodlands, Spring and Woodforest, Monday through Friday, 8:00 AM to 5:00 PM.
Common questions
How long does a knee replacement last?
In the largest registry analysis to date, about 82% of total knee replacements were still in place at 25 years, and about 70% of partial knees (Evans et al., 2019). AAOS patient guidance puts it at more than 90% still working at 15 years (OrthoInfo).
What is the chance I'll need a second surgery?
Low. The American Joint Replacement Registry reports a revision rate of 0.83% one year after total knee replacement and 2.60% at ten years (AJRR, 2024) — roughly one patient in forty over a decade.
Does a partial knee replacement last as long as a total?
Not quite, on average. The same 25-year registry data shows about 70% of partial knees still in place versus about 82% of total knees (Evans et al., 2019). A partial knee trades some durability for a smaller operation and a quicker early recovery, and is only an option when one compartment is worn. About partial knee replacement →
What happens if my knee replacement wears out?
A revision replaces the worn or loose parts, and it is a more complex operation than the first one. At Sterling Ridge, Dr. Rohan Gheewala, adult reconstruction fellowship-trained at Baylor College of Medicine, handles complex and revision knees. About revision surgery →
Sources
- Evans JT et al. 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.
- American Joint Replacement Registry. 2024 Annual Report highlights.
- AAOS OrthoInfo. Total Knee Replacement.
- Ruangsomboon P et al. Robotic-assisted versus conventional total knee arthroplasty: meta-analysis of randomized trials, 2023.
- AAOS. Clinical Practice Guideline for Surgical Management of Osteoarthritis of the Knee, 2023 update.
Medically reviewed by Keith W.V. Johnson, MD, FAAOS · Updated October 20, 2026