Adductor Canal Block Versus Femoral Nerve Block for Analgesia After Total Knee Arthroplasty: A Systematic Review and Meta-analysis

Abstract

Objectives: The efficacy and safety of adductor canal block (ACB) as compared with femoral nerve block (FNB) for postoperative pain management in total knee arthroplasty (TKA) remains controversial. We therefore performed a meta-analysis of randomized-controlled trials (RCTs) to compare ACB with FNB in TKA.

Materials and methods: Databases, including Pubmed, Medline, Embase, Web of Science, and Cochrane library were searched to identify RCTs comparing ACB with FNB for pain management in patients undergoing TKA. The primary outcomes included pain score with rest or activity and opioid consumption. Secondary outcomes were mobilization ability, quadriceps strength and grade, length of hospital stay, and complications (nausea or vomiting).

Results: A total of 573 TKAs in 514 patients from 7 RCTs were included in the meta-analysis. Two studies with 155 TKAs reported the mobilization ability assessed by Timed Up and Go Test. The ACB patients performed significantly faster than the FNB patients in the early postoperative period (mean difference=-5.08; 95% confidence interval, -6.03 to -4.13; P<0.00001). The subgroup analysis showed that the outcomes of pain, morphine consumption, quadriceps strength, and length of hospital stay in single shot and continuous subgroups were not statistically different between the 2 groups (P>0.05).

Discussion: ACB may achieve faster mobilization ability recovery for patients after TKA without a reduction in analgesia when compared with FNB in the early postoperative period. However, due to the variations in the included studies, additional studies are needed to validate these conclusions.