Careful patient selection is critical for unicompartmental knee arthroplasty if reliable results are to be achieved. The disease should be predominantly confined to a single compartment.Resurgence of the interest in the unicompartmental arthroplasty has occurred, particularly with the introduction of more physiologic new implant designs that have achieved acceptable long-term results. Interest in the procedure was also stimulated by the introduction of the minimally invasive technique.Advantages of UKA include preservation of uninvolved tissue and bone, reduced operative time, better range of motion, improved gait, and increased patient satisfaction.