Nerve blocks curb opioid use after knee ligament surgery, review finds

Adults undergoing anterior cruciate ligament reconstruction under general anesthesia may receive less opioid medication in the first day after surgery when they receive certain regional nerve blocks, according to a systematic review and network meta-analysis published in BMC Anesthesiology. The analysis pooled randomized controlled trials comparing regional and local analgesic techniques, and found that femoral nerve block alone and femoral nerve block combined with sciatic nerve block were associated with lower estimated opioid consumption at 24 hours postoperatively than control, measured in oral morphine milligram equivalents.

The researchers searched PubMed, Embase, the Cochrane Library, and Web of Science from inception to February 18, 2026, and included 31 randomized controlled trials covering 2,470 patients. Risk of bias was assessed with the revised Cochrane risk-of-bias tool, and the data were synthesized using a Bayesian random-effects network meta-analysis, a statistical approach that allows both direct and indirect comparisons across multiple treatments within a single network. Only six of the included studies were judged to be at low risk of bias, a limitation that shaped the certainty of the findings.

For opioid consumption at 24 hours, femoral nerve block was associated with a mean difference of −30.31 oral morphine milligram equivalents compared with control (95% credible interval −58.02 to −6.79), while the combination of femoral and sciatic nerve block showed a mean difference of −40.42 (95% credible interval −80.42 to −5.79). The combined femoral and sciatic block ranked highest for lowering 24-hour opioid use, with a surface under the cumulative ranking curve value of 87.44%, a measure that summarizes a treatment’s probable rank across the network.

Pain score comparisons showed more selective benefits. Femoral nerve block combined with graft donor-site infiltration was associated with lower estimated pain scores in the post-anesthesia care unit than local infiltration analgesia (mean difference −2.46, 95% credible interval −4.67 to −0.21). At 24 hours, adductor canal block combined with graft donor-site infiltration had lower estimated pain scores than adductor canal block alone (mean difference −1.50, 95% credible interval −2.43 to −0.61). At 48 hours, however, the credible intervals for all pain comparisons included zero, meaning no difference could be distinguished at that time point.

One comparison favored a more complex technique on a different outcome: adductor canal block combined with infiltration between the popliteal artery and the capsule of the posterior knee, a procedure known as iPACK, was associated with a longer estimated time to first analgesic request than adductor canal block alone, with a mean difference of 7.50 (95% credible interval 1.92 to 13.01). For postoperative nausea and vomiting, the credible intervals for all comparisons included 1, indicating no clear differences among the techniques for this outcome.

The strength of the key findings weakened considerably in sensitivity analyses. When the authors excluded studies judged to be at high risk of bias, the credible intervals for the main comparisons on opioid consumption and time to first analgesic request widened and included zero, meaning the apparent advantages could no longer be distinguished from no effect. Some treatment nodes were missing from certain outcome networks, and the rankings for postoperative nausea and vomiting changed in these analyses, underscoring how sensitive network meta-analysis results can be to the composition of the evidence base.

The authors also noted important gaps in scope. Functional outcomes were not systematically synthesized, and the assessment of adverse events was limited to postoperative nausea and vomiting, leaving other complications of nerve blocks, such as nerve injury or motor weakness, outside the quantitative comparison. The conclusion states explicitly that although potential analgesic benefits varied across outcomes, the key estimates became less precise after high-risk studies were excluded, and that these findings do not establish the overall clinical superiority of any single strategy.

For clinicians and patients, the practical message is one of cautious, outcome-specific interpretation rather than a single best choice. The evidence suggests that femoral nerve block, alone or with sciatic nerve block, may reduce opioid requirements in the first 24 hours after ACL reconstruction, and that adding graft donor-site infiltration to certain blocks may improve early pain scores. But because the estimates rest largely on trials with elevated risk of bias and lose precision when those trials are removed, the review’s authors frame their results as hypothesis-generating. The article, published open access on October 29, 2026, was shared early as a citable version of record pending final edits, and the authors report no clinical trial registration number for the review itself.

Subject of Research: Comparing regional and local analgesic techniques for pain control after anterior cruciate ligament reconstruction in adults under general anesthesia

Article Title: Analgesic efficacy of regional and local analgesic techniques for anterior cruciate ligament reconstruction in adults undergoing general anesthesia: a systematic review and network meta-analysis

Article References: Xu, L., Chen, K., Yang, C., & Jiang, P. (2026). Analgesic efficacy of regional and local analgesic techniques for anterior cruciate ligament reconstruction in adults undergoing general anesthesia: a systematic review and network meta-analysis. BMC Anesthesiology. https://doi.org/10.1186/s12871-026-04387-6

Image Credits: AI Generated

DOI: 10.1186/s12871-026-04387-6

Keywords: anterior cruciate ligament reconstruction, femoral nerve block, sciatic nerve block, adductor canal block, network meta-analysis, opioid consumption, postoperative pain, regional anesthesia, systematic review, risk of bias, postoperative nausea and vomiting, BMC Anesthesiology