To compare adductor canal block (ACB) with femoral nerve block (FNB) for postoperative analgesic effect and early rehabilitation after total knee arthroplasty (TKA).

The Cochrane Library, PudMed, EMBASE, CNKI, VIP and Wan Fang were searched to identify randomized controlled trials (RCTs) articles comparing the ACB with the FNB in TKA up to August 2016. Study selection and assessment, data collection and analysis were undertaken by two authors independently. The meta-analysis was performed using Review Manager 5.2.0, and publication bias was evaluated through a funnel plot.

Twelve studies were included, involving nine English studies and three Chinese studies There was a total of 772 cases comparing ACB (n=382) with FNB (n=390). Meta-analysis suggested that the resting VAS scores[WMD=0.20, 95%CI(-0.33, 0.72); WMD=0.24, 95%CI(-0.12, 0.60); WMD=0.31, 95%CI(-0.07, 0.69); WMD=0.03, 95%CI(-0.29, 0.35)] and motion VSA scores[WMD=0.10, 95%CI(-0.41, 0.62); WMD=0.64, 95%CI(0.15, 1.12); WMD=0.17, 95%CI(-0.37, 0.70); WMD=0.03, 95%CI(-0.57, 0.62)]were similar to the ACB group and FNB group at 2-4 h, 6-8 h, 24 h and 48 h. The quadriceps strength in the ACB group was better than that in the FNB group at 4 to 8 h, 24 h and 48 h[WMD=0.45, 95%CI(0.25, 0.64); WMD=0.38, 95%CI(0.14, 0.61); WMD=0.41, 95%CI(0.18, 0.63)]. The range of motion in the ACB group was also better than that in the FNB group at 24 h, 48 h and 72 h[WMD=5.01, 95%CI(0.78, 0.92); WMD=8.74, 95%CI(3.54, 13.93); WMD=6.65, 95%CI(1.97, 11.33)]. Besides, ACB group had advantages in time-up-go test[WMD=-55.98, 95%CI(-109.60, -2.35)] and length of hospital stay[WMD=-0.049, 95%CI(-0.96, -0.03)]. There was no difference in opioid consumption and side effect of nausea and vomiting.

When comparing with FNB, the ACB shows similar postoperative analgesia effects and has advantages in quadriceps strength recovery and promoting early postoperative rehabilitation, but more high-quality RCTs are required for further investigation.