A partial knee replacement is a surgery to replace only one part of a damaged knee. It can replace either the inside (medial) part, the outside (lateral) part, or the kneecap part of the knee.
Surgery to replace the whole knee joint is called total knee replacement.
Partial knee replacement surgery removes damaged tissue and bone in the knee joint. It is done when arthritis is present in only part of the knee. The areas are replaced with an artificial implant, called a prosthetic. The rest of your knee is preserved. Partial knee replacements are most often done with smaller incisions, so there is less recovery time.