Authors: Topalidou X et al.
A & A Practice 20(1): e02104, January 2026, 10.1213/XAA.0000000000002104
This systematic review and meta-analysis evaluated whether the adductor canal block (ACB) improves postoperative outcomes for patients undergoing total knee arthroplasty (TKA) when compared with local infiltration analgesia (LIA) alone. The investigators analyzed randomized controlled trials comparing ACB alone or ACB combined with LIA versus LIA alone.
A total of 26 randomized controlled trials including approximately 2,400 patients were included. Databases searched included MEDLINE, PubMed Central, Cochrane Library, and Scopus through December 2024. The primary outcome was postoperative pain at 24 and 48 hours using either visual analog scale (VAS) or numerical rating scale (NRS). Secondary outcomes included opioid consumption, knee range of motion (ROM), length of hospital stay, and postoperative nausea and vomiting (PONV).
The most consistent benefit occurred when ACB was combined with LIA. Compared with LIA alone, ACB plus LIA significantly reduced both resting and activity-related pain scores at 24 hours and 48 hours after surgery. The standardized mean differences showed moderate improvements in pain control, particularly during movement. Pain during activity showed the largest effect size, indicating that the block most strongly improves functional pain rather than purely resting pain.
ACB alone showed a more limited benefit. When compared to LIA alone, ACB by itself significantly reduced pain during activity but did not significantly reduce pain at rest. This finding is consistent with the motor-sparing nature of the block, which preserves quadriceps strength while improving functional analgesia.
Patients receiving ACB combined with LIA also demonstrated reduced opioid consumption and improved knee range of motion at 24 hours postoperatively. These findings suggest that improved analgesia translated into earlier functional recovery. However, these benefits did not persist across all time points, and later outcomes such as overall length of hospital stay were not significantly different between groups.
Another notable finding was a lower incidence of postoperative nausea and vomiting in patients who received ACB. This is likely related to the reduction in opioid use rather than a direct effect of the nerve block itself.
Despite these findings, the authors emphasize limitations in the available literature. The certainty of evidence ranged from moderate to very low according to GRADE criteria, and many studies demonstrated moderate to high risk of bias. Heterogeneity among studies, particularly in block technique, local anesthetic concentration, and infiltration protocols, also limits the strength of conclusions.
Overall, the review supports the concept that adductor canal block is an effective component of multimodal analgesia for total knee arthroplasty, particularly when combined with local infiltration analgesia.
What You Should Know
Adductor canal block continues to gain popularity because it provides analgesia while largely preserving quadriceps strength, which helps early mobilization after knee replacement.
This meta-analysis supports combining ACB with local infiltration analgesia rather than relying on either technique alone.
The most clinically meaningful benefit appears to be improved pain control during movement rather than at rest, which is important for early physical therapy and ambulation.
The addition of ACB may also reduce opioid requirements and decrease postoperative nausea and vomiting.
However, the quality of evidence remains variable and the analgesic benefit, while statistically significant, is modest.
Key Points
Twenty-six randomized trials with approximately 2,400 patients were analyzed.
ACB combined with LIA significantly reduced pain scores at both 24 and 48 hours compared with LIA alone.
ACB alone improved pain during activity but did not significantly improve resting pain.
ACB plus LIA reduced opioid consumption and improved early knee range of motion.
Lower rates of postoperative nausea and vomiting were observed in patients receiving ACB.
Thank you to A & A Practice for allowing us to summarize this article.