Objective:To evaluate the effect of adductor canal block(ACB)and local infiltration anesthesia(LIA)around the knee joint on inflammatory responses in the patients undergoing total knee arthroplasty(TKA).Methods:Sixty American Society of Anesthesiologists physical status Ⅱor Ⅲ patients of both sexes, aged 54-76 yr, scheduled for elective TKA, were divided into 2 groups ( n=30 each) using a random number table method: ACB group (group A) and ACB combined with LIA around knee joint group (group AL). ACB was performed with 0.5% ropivacaine 15 ml after endotracheal intubation in group A and group AL, and in addition LIA was performed around the knee joint after the osteotomy was completed during surgery in group AL.The patient-controlled ACB analgesia was applied at the end of surgery in both groups.The analgesic solution contained ropivacaine 400 ml (in 0.9% normal saline 200 ml), and the analgesic pump was set up to deliver a 5 ml bolus dose with a 30-min lockout interval and background infusion at 5 ml/h.When visual analog scale score>4, and pain was still not relived at 30 min after pressing by patients, pethidine hydrochloride 100 mg was intramuscularly injected as rescue analgesic.Peripheral venous blood samples were collected immediately before surgery (T 0) and at 24, 48 and 72 h after surgery (T 1-3) for determination of serum interleukin-6 (IL-6) and IL-10 concentrations by enzyme-linked immunosorbent assay.The muscle strength on the affected side was assessed at T 1-3.The patients′ satisfaction score, requirement for rescue analgesia, and adverse effects were recorded. Results:Compare with group A, the serum IL-6 concentrations were significantly decreased and serum IL-10 concentrations were increased at each time point after surgery, postoperative patients′ satisfaction scores were increased, the requirement for rescue analgesia was decreased ( P<0.05), and no significant change was found in the quadriceps strength of the affected limb and incidence of adverse reactions after surgery in group AL ( P>0.05). Conclusion:ACB and LIA around the knee joint can mitigate postoperative inflammatory responses in the patients undergoing TKA.