Last reviewed: September 29, 2026

For most people, a very long time. Large national joint registries show that about 9 in 10 knee replacements are still in place 15 to 20 years after surgery, and about 8 in 10 at 25 years. No knee replacement lasts forever, but many people never need a second operation.

Age at surgery matters most. The younger you are when you have it, the more likely you are to need a redo someday. For people over 70 at surgery, the lifetime chance is about 1 in 20. That figure comes from a study that combined hips and knees. For men in their late 40s, it is about 1 in 4. Among younger patients, men are more likely than women to need a redo. People in poorer general health are more likely to need one at every age.

The most common reasons for a redo are loosening of the parts, an unstable knee, infection, and pain without a clear cause.

These numbers describe large groups. They cannot tell you what your own knee will do.

In general:

  • Most knee replacements last 20 years or more.
  • The younger you are at surgery, the more likely you are to need a redo someday.
  • If you are younger, weigh this with your surgeon when deciding when to have surgery.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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