A partial knee replacement replaces only the WORN part of your knee, usually the inner side, and keeps the healthy parts and your own ligaments.
Compared with a total knee replacement, recovery is usually quicker, the hospital stay is shorter, and many people say the knee feels more natural. The trade-off is a higher chance of needing a redo operation later.
It only suits people whose arthritis is limited to one part of the knee, with stable ligaments.
Who it suits
- Arthritis in one part of the knee only, most often the inner side, confirmed on X-ray
- Stable knee ligaments, including a working ACL
- A knee that still bends and straightens reasonably well
- Not a good fit for inflammatory arthritis like rheumatoid, or when arthritis affects the whole knee
- More people may be suitable than actually get one. If you’re told you need a total knee, it’s fair to ask whether a partial was considered
Partial vs total
- Recovery: usually faster with a partial. Many people go home the same day or the next
- How it feels: often more like a natural knee, because your own ligaments stay
- Complications: generally fewer serious complications than a total in the short term
- Redo surgery: more likely than with a total over the years, often because arthritis develops in another part of the knee
- Results at five years: in a large UK trial of people suitable for either, both did about equally well, and the partial was better value
A smaller operation and a faster recovery, in exchange for a higher chance of a second one later.
Recovery, roughly
- Days 0 to 2: walking with a frame or crutches, often home the same day or the next
- Weeks 1 to 3: walking aids for short distances, then often a stick or nothing. Getting the knee straight and bending comes first
- Weeks 3 to 6: most daily activities back. Stationary bike and strengthening
- Weeks 6 to 12: longer walks, most sports that don’t involve impact
- Up to six months: swelling and stiffness keep easing, and strength keeps building
The same basics apply as with a total knee: get it straight early, keep the swelling down, and build the thigh muscle. See knee replacement recovery week by week.
When can I…
- Drive: often around 3 to 6 weeks, once you’re off strong painkillers and can brake hard. Check with your surgeon and insurer
- Go back to a desk job: often 2 to 4 weeks
- Go back to a job on your feet: usually 6 to 8 weeks
- Kneel: it may be uncomfortable for a while, but it won’t damage the implant
- Play sport: walking, cycling, swimming, golf and doubles tennis are usually fine. High-impact sports are often discouraged
Questions to ask your surgeon
- Is my arthritis limited to one part of the knee?
- Am I suitable for a partial, and if not, why not?
- How many partial knee replacements do you do each year? Results are better with surgeons who do them often
- What happens if the rest of the knee wears later?
Call your surgeon today if
- The wound is red, spreading, weeping or leaking, or you have a fever
- Your calf is painful, swollen or warm
- You’re short of breath or have chest pain. Call emergency services
- Pain is getting worse instead of better
Before surgery, see knee arthritis: what actually helps.
If only one part of your knee is worn, ask whether only one part needs replacing.