The purpose of this study was to validate the 'Forgotten Joint' score (FJS-12), a 12-item questionnaire designed to analyze the patient's ability to forget the joint in everyday life, in French and to compare the results of this Patient Reported Outcome (PRO) score in patients who had other than total joint arthroplasties. The score was compared in 122 patients that had either medial unicompartmental (N=51), patellofemoral (N=21) or total knee arthroplasty (N=50). After having validated the FJS-12 in French, a similar PRO was observed in unicompartmental and postero-stabilized total knee arthroplasty. Patellofemoral resurfacing had a significantly lower score than the two other types of arthroplasty, which can be explained by a significantly younger and smaller patient group.