 The objective of this prospective study is to determine 1 the time course of patient-relevant functional outcome evaluated by the Knee injury and Osteoarthritis Outcome Score KOOS and 2 the time course of range of motion ROM the first six years following Oxford Medial Unicondylar Knee prosthesis. Improvement of patient self-reported pain and daily function during the study period, are of particular interest. Thats it! 