Combined application of adductor canal block and local infiltration anesthesia in primary total knee arthroplasty: an updated meta-analysis of randomized controlled trials

Perioperative pain after total knee arthroplasty (TKA) may seriously affect the rapid recovery of patients. The purpose of this study was to assess whether the combined use of adductor canal block (ACB) and local infiltration anesthesia (LIA) can further reduce postoperative pain and improve early functional recovery. PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials were systematically searched for randomized controlled trials (RCTs) comparing ACB + LIA and LIA alone in primary TKA. The primary outcomes were visual analog scale (VAS) scores at rest and walking, morphine consumption, range of motion (ROM) at 24 and 48 h postoperatively and distance walked. The secondary outcomes were the length of stay, the incidence of nausea and vomiting, and the total complications. Subgroup analyses were performed on the VAS at rest and walking, morphine consumption, and distance walked at 24, 48, and 72 h postoperatively. A total of 10 RCTs involving 797 patients were enrolled in this meta-analysis. The results demonstrated that the combined application of ACB + LIA had a lower resting VAS at 24 h postoperatively (p = 0.02) and the walking score at 24 (p = 0.0002) and 48 h (p = 0.02) postoperatively compared with LIA alone. Similarly, the combined ACB + LIA group also had less morphine consumption at 48 h postoperatively (p = 0.0005) and had a higher ROM score at 24 h (p = 0.01) postoperatively compared to the LIA group. There were no statistical differences in length of stay, distance walked, and incidence of nausea and vomiting. The current meta-analysis showed that ACB + LIA significantly reduced postoperative walking pain and morphine consumption and promoted rapid recovery in the early postoperative period. There is no statistical difference in the length of stay and ROM after 72 h in the two groups.