What it is
Also called a unicompartmental or 'uni' knee replacement. When arthritis affects only one part of the knee (usually the inside), just that part is resurfaced, and the rest of the knee and its ligaments are kept.
Who it's usually for
People whose arthritis is limited to one part of the knee, with healthy ligaments. It isn't suitable when arthritis is spread through the whole knee.
Pros and cons
✓ Pros
- Smaller operation with a faster recovery for many people.
- The knee often feels more natural and bends further.
- Less blood loss and fewer early complications on average.
⚠ Cons and risks
- Higher chance of needing another operation later than with a total knee.
- Arthritis can develop in the parts of the knee that were kept.
- Only suitable for some patients; results depend a lot on choosing the right patient.
Recovery times are typical ranges; yours may be different. Your surgeon can tell you what to expect.
What recovery is like
Exercises start right away, like a total knee, but most people find the recovery gentler and faster.
Questions to ask your surgeon
- Is my arthritis really limited to one part of the knee?
- How many partial knees do you do each year?
- What happens if I need a total knee later?
When to get help quickly: Get help the same day for a hot, red, swollen joint with fever, if you can't put weight on your leg after an injury, or, after surgery, for fever, wound drainage, or new calf pain or swelling. For chest pain or sudden shortness of breath, call 911.
What surgeons say in their videos
Videos from different surgeons and doctors, newest first. They share their own views, and we don't rank or endorse any of them.
Common questions about partial knee replacement
What is partial knee replacement?
Also called a unicompartmental or 'uni' knee replacement. When arthritis affects only one part of the knee (usually the inside), just that part is resurfaced, and the rest of the knee and its ligaments are kept.
Who is partial knee replacement for?
People whose arthritis is limited to one part of the knee, with healthy ligaments. It isn't suitable when arthritis is spread through the whole knee.
What is recovery like after partial knee replacement?
Exercises start right away, like a total knee, but most people find the recovery gentler and faster.
How long is the hospital stay for partial knee replacement?
Typically often same day.
What are the risks of partial knee replacement?
Higher chance of needing another operation later than with a total knee. Arthritis can develop in the parts of the knee that were kept. Only suitable for some patients; results depend a lot on choosing the right patient.
Getting ready
Losing extra weight, exercising before surgery, stopping smoking and getting your home ready can make surgery safer and recovery easier.
How to get ready for surgery →Find a surgeon
Look up hip and knee surgeons in your state, from public records.
Find a hip & knee surgeon →Other knee surgeries
Sources
We base this page on these major medical organizations and studies. How we write our pages.
General information written for Hip & Knee Surgery, not by the surgeons in the videos. For education only; not medical advice. Last reviewed October 2026.