Knee arthroplasty is a successful surgical treatment for end-stage osteoarthritis. Most patients are satisfied with the result, however, 10% of the patients have remained dissatisfied over the last decades despite the advantages of the surgical procedure. Previous studies suggest that rehabilitation needs to be individualized and that some patients request additional support. Patient empowerment is a patient-centered strategy to increase, amongst other, patient engagement, participation, and motivation. Patient empowerment can be defined as a process that helps people gain control over their own lives and increases their capacity to act on issues that they themselves define as important. One way of increasing patient empowerment is through motivational interviewing. Motivational interviewing is an evidence-based approach in which patients are supported to identify behavior changes toward their own individual goals. The aim of this study is to investigate if motivational interviewing could increase satisfaction in patients undergoing knee arthroplasty. Furthermore, we want to examine role MI in this patient group with interviews of both MI-practitioners and patients as well as detailed investigations about the MI sessions.