Patients 19-75 years old, of ASA classification I-III scheduled for unilateral TKA, will be enrolled and randomized into two groups, single-shot ACB group and continuous ACB group. In both groups, participants will be administered a single-shot ACB immediately after the end of the operation. The single-shot ACB group will receive two separate single-shot ACBs, on the first and second postoperative day. A nerve block catheter will be placed in patients in the continuous ACB group, which will be connected to a patient-controlled analgesia pump until the second postoperative day. The primary outcome of this study is the average NRS pain score at rest from the end of surgery to 2 days after surgery.
This study will compare the analgesic efficacy of daily single-shot adductor canal block(ABC) versus continuous ACB after total knee arthroplasty (TKA).