Replacing part of the knee joint with an implant - this could be one of the tibiofemoral joints or/and the patellofemoral joint.
Patient relevant outcomes of unicompartmental versus total knee replacement: systematic review and meta-analysis. Wilson HA, Middleton R, Abram SGF, Smith S, Alvand A, Jackson WF, Bottomley N, Hopewell S and Price AJ. BMJ. 2019; 364: l352.