Abstract: Objective To evaluate the analgesic effect of ultrasound-guided genicular nerve block(GNB)and local infiltration analgesia(LIA)after total knee arthroplasty(TKA). Methods A total of 60 patients undergoing unilateral TKA under general anesthesia were randomsied into LIA and GNB groups, with 30 patients in each group. After induction of general anesthesia, the GNB group underwent ultrasound-guided GNB(20 mL of 0.2% ropivacaine)while the LIA group received periarticular LIA(100 mL of 0.2% ropivacaine)before the end of surgery. The primary outcome was the numerical rating scale(NRS)score at rest at 24 h postoperatively. Secondary outcomes included the NRS scores at rest(6, 48 h)and during movement(6, 24, 48 h), sufentanil consumption at 24 h and 48 h, 20 m walk test times at 24 h, nausea and vomiting at 48 h postoperatively, patient satisfaction and hospital stay. Results Compared to the LIA group, patients in the GNB group had significantly lower NRS scores at rest(3.6±1.0 vs. 2.4±0.8, P<0.001)and during movement(5.4±1.4 vs. 3.9±1.1, P<0.001)at 24 h postoperatively and at rest(4.2±1.2 vs. 3.4±0.9, P=0.010)and during movement(5.7±1.4 vs. 4.4±1.2, P<0.001)at 48 h postoperatively. Sufentanil consumption in the GNB group was significantly lower than in the LIA group at both 24 h ［(56.9(49.2-62.4)vs. 43.1(38.5-48.1), P<0.001］ and 48 h ［90.4(85.1-105.5) vs. 81.7(75.9-90.6), P=0.002］ postoperatively. The two groups showed no significant difference in NRS score at 6 h postoperatively, nausea and vomiting within 48 h, 20 m walk test times at 24 h, satisfaction scores and hospital stay(P>0.05). Conclusion Compared with LIA, ultrasound-guided GNB can significantly reduce pain scores and opioid consumption at 24 and 48 h postoperatively in TKA patients.

Key words: Total knee arthroplasty, Local infiltration analgesia, Genicular nerve block, Enhanced recovery after surgery, Postoperative pain