Total knee replacement
Most total knee replacement operations involve replacing the joint surfaces at the end of your thigh bone (femur) and at the top of your shin bone (tibia).
A total knee replacement may also involve replacing the under-surface of your kneecap (patella) with a smooth plastic dome. Some surgeons prefer to preserve the natural patella if possible, but sometimes the decision will need to be made during the operation.
If you’ve had a previous operation to remove the patella altogether (patellectomy), this won’t stop you having a knee replacement, but it may affect the type of replacement part (prosthesis) your surgeon uses.
The new parts are normally cemented in place. If cement is not used then the surface of the component facing the bone is textured or coated to encourage bone to grow onto it, forming a natural bond.
Another common technique is to use a mobile plastic bearing which isn’t firmly fixed to the metal parts. This may help to reduce wear on your new joint, though it isn’t hasn't been shown to provide better long-term results.