Total knee arthroplasty (TKA) is a very common procedure, with more than 600.000 being performed annually in the US alone. This number is expected to increase to more than 3 million by 2030. The procedure is associated with intense, early postoperative pain, and half of the patients report moderate to severe pain the first 2-3 postoperative days (POD). Peripheral regional anesthesia (PRA) using single injection nerve blocks is highly recommended as part of a multimodal, perioperative, analgesic treatment.