Postoperative rehabilitation after knee arthroplasty surgery is considered to be of vital importance. The severe Spanish lockdown during the first wave of the COVID pandemic forced patients to stay at home shortly after their knee surgery. This study compares the clinical outcome after 6 months between patients that completed the postoperative rehabilitation protocol and those that did not receive any professional rehabilitation at all. 146 consecutive knee arthroplasty surgeries were enclosed in this study, 46 of them with no postoperative rehabilitation at all. The result of this study showed no inferior clinical outcome for the group without any rehabilitation.