Single shot versus continuous technique adductor canal block for analgesia following total knee arthroplasty: A PRISMA-compliant meta-analysis

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.