Background: An adductor canal block (ACB) provides recognized analgesia following total knee arthroplasty (TKA). This meta-analysis compared the single-injection ACB (SACB) with the continuous-injection ACB (CACB).
Method: Relevant studies were searched from PubMed (1996-October 2018), Embase (1980-October 2018), and Cochrane Library (CENTRAL, October 2018). Four randomized controlled trials (RCTs), which compared SACB with CACB, were included in our meta-analysis.
Results: Four RCTs met the inclusion criteria. Our pooled data indicated that the SACB group had similar efficacy compared with the CACB group in terms of morphine consumption (P = .19), time to first opioid request (P = .32), range of motion (P = .97), and visual analogue scale (VAS) scores at 24 hours at rest (P = .12) and movement (P = .24), without increasing the risk of complications (P = .97) and length of stay (P = .54).
Conclusion: The SACB technique provides similar analgesia in the 24 hours following TKA compared with CACB, while the CACB method was better over 48 hours.