Partial knee replacement (also known as unicompartmental knee arthroplasty or unicondylar knee arthroplasty) is a surgical treatment for knee arthritis. This treatment is suitable for people who experience arthritis only in one compartment (section) of the knee joint, rather than throughout the joint. It can also provide relief from pain and stiffness in some people who have medical conditions that make them poor candidates for total knee replacement surgery (condylar arthroplasty).
In a partial knee replacement, damaged cartilage and bone are removed and replaced only in the diseased compartment of a person's knee. This differs from a total knee replacement, in which bone and cartilage from the entire joint are replaced.