The development and implementation of "fast-track" principles in total knee and hip arthroplasty have resulted in early recovery and rehabilitation alongside a reduced length of hospital stay. This without a concomitant increase in morbidity or readmissions for medical or surgical complications and with reduced mortality. However, only little is known about function in the subacute period after arthroplasty, and there is a need for further data on physical and psychological functioning following discharge from hospital.This to ensure, that the positive results from the perioperative setting are carried forward in the subacute phase.