 MATERIALS METHODS The study is performed as a randomized clinical trial. In total 140 patients are included in the study. Inclusion criteria are age above 18 years, patients diagnosed as having knee arthrosis, patients receiving primary elective TKA, and patients who are able to and willing transport themselves to the rehabilitation center, which demands ability to walk 50 meter, and climb 10 stair steps. Exclusion criteria are unicompartmental or revision arthroplasty, any neurological disease, knee infection, and substantial pain or functional limitation hindering rehabilitation tested by physiotherapist prior to rehabilitation start. Primary endpoint is 6 months postoperatively and primary outcome measure is change in total score by using the knee specific questionnaire Oxford Knee Score. 