Effect of Adductor Canal Block Combined with Local Infiltration Analgesia on Postoperative Pain of Knee Arthroscopy Under General Anesthesia: A Randomized Controlled Trial.

Introduction: Postoperative pain in knee arthroscopy (KA) is a common and troublesome problem. The best local analgesic technique for relieving postoperative pain in patients with KA has not been well studied. This prospective trial aimed to observe whether adductor canal block (ACB) combined with local infiltration analgesia (LIA) could further decrease the incidence of postoperative pain undergoing KA.

Methods: This randomized controlled study recruited 60 patients aged 18-65 years, ASA I-II, who received KA, and randomly divided them into ACB + LIA group and LIA group. The primary outcome was the incidence of postoperative pain 24 h after surgery. The secondary outcomes included the incidence of quadriceps femoris weakness, and the consumption of opioids during operation.

Results: A total of 60 participants completed the trial. The incidence of postoperative pain 24 h after surgery in ACB + LIA group was lower than that in the LIA group (10% [3 of 30] vs. 33% [10 of 30]; P = 0.028). There was no difference in the incidence of quadriceps muscle weakness 24 h after surgery between the two groups. The consumption of remifentanil and sufentanil in ACB + LIA group was significantly lower than that in LIA group (P = 0.006, P < 0.001).

Conclusions: Compared with patients receiving LIA alone, ACB combined with LIA could reduce the incidence of postoperative pain while retaining the strength of the quadriceps femoris in patients undergoing KA and reduce the consumption of opioids during surgery.

Clinical Trial Number And Registry Url: This study was registered at the Chinese Clinical Trial Registry with the registration number ChiCTR1800018463 on September 20, 2018. ( http://www.chictr.org.cn/showproj.aspx?proj=31192 ).