Adductor canal block (ACB) provides effective analgesia following total knee arthroplasty (TKA). This systematic review aimed to compare continuous and single-shot ACB for pain management and functional recovery following TKA.

MEDLINE, Embase, Web of Science and CENTRAL were searched up to January 5th, 2021. Included studies were randomized controlled trials comparing continuous to single-shot ACB for postoperative pain management after primary TKA. Primary outcome was opioid consumption and secondary outcomes were pain intensity, quadriceps strength, mobility, complications, and length of hospital stay. Meta-analyses were performed using random-effects method.

Eleven studies (910 patients) were included in this systematic review. Continuous ACB did not significantly decrease opioid consumption (8 studies; 642 patients; MD=−5.67; 95% CI: −13.87 to 2.54; I²=13%) but significantly decreased 48hours pain scores (10 studies; 852 patients; MD=−0,73; 95% CI: −0.93 to −0.54; I²=54%). Continuous ACB improved quadriceps strength (4 studies; 250 patients; SMD=0.59; 95% CI: 0.16 to 1.03; I²=63%) but not Timed Up and Go test performance (5 studies; 524 patients; MD=3.99; 95% CI: −8.98 to 1.01; I²=89%). Type of ACB did not affect nausea and vomiting (5 studies; 357 patients; RR=1.23; 95% CI: 0.65 to 2.34; I²=0%) nor length of hospital stay (8 studies; 655 patients; MD=−0.13; 95% CI: −0.28 to 0.01; I²=36%).

Continuous ACB did not reduce opioid consumption following TKA. Larger trials are required.