In unicompartmental knee replacement (also called "partial" knee replacement) only a portion of the knee is resurfaced. This procedure is an alternative to total knee replacement for patients whose disease is limited to just one area of the knee. partial knee replacement is often preferred in the younger population as their recovery is quicker and often with much less pain. About 5% to 6% of patients with arthritic knees are estimated to be eligible for partial knee replacement.