Another alternative is partial (commonly known as "uni") knee replacement, which is performed when only one condyle of the knee is affected by arthritis. Surgeons generally use a small incision to remove the joint surface and a small amount of bone, replacing them with the implant. The recovery period is also usually shorter than with a total knee replacement. Many people can return to walking in two to four weeks, although physical therapy may still be needed to restore knee strength and function.