Treatment options for an arthritic joint ranges from nutritional supplements to prescription medications to injections. When severe pain persists despite all of these, joint replacement is an option. For the knee, this usually means a total knee replacement.

However, many patients are candidates for a surgery with a shorter hospital stay, shorter and less painful recovery, and a more cosmetic incision. This surgery is a partial knee replacement, also knows as the uni-condylar knee. This is an option for patients with arthritis affecting primarily the inner or the outer side of the knee, but not both to the same degree. This wear pattern is fairly common since most people with arthritic knees are a touch more knock-kneed (which will wear the outer side) or bow-legged (which will wear the inner side) than average. Rather than replacing the entire knee, only the severely worn portions are replaced. This allows the patient to have a smaller scar, less blood loss, and less pain than with a total knee replacement. Also, more of the normal anatomy of the knee, including the internal ligaments, are preserved rather than being replaced.

The overall result is a knee which behaves much more like a normal knee. Whether someone is a candidate for a uni-condylar knee is determined by their symptoms, special x-rays looking at all surfaces of the knee, and a careful physical exam.