“…So many authors tried to optimize the dosage and concentration of bupivacaine for ambulatory knee surgery, but achieved only a recovery profile comparable to GA [8][9][10]. In 2010, after introduction of hyperbaric prilocaine 2% to the German market, a medium-long acting local anesthetic with pharmacological characteristics comparable to lidocaine and mepivacaine but a remarkable lower incidence of TNS, a nearly perfect substance for this indication seemed to be available [11]. We assumed that due to a shorter duration of action of prilocaine compared to bupivacaine, a SPA could lead to a faster recovery than a GA.…”