Most Analgesia Treatments Have No Clinical Significance for Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis of 66 Randomized Controlled Trials

Purpose: To assess the relative efficacy of several clinical treatments for postoperative analgesia of anterior cruciate ligament reconstruction through network meta-analysis based on multiple published randomized controlled trials.

Methods: We searched PubMed, the Cochrane library, EMBASE, and Web of Science, each from inception until February 15, 2021. Outcomes including pain scores at rest (visual analog scale, numerical rating scales, and other scales, which were converted to a standardized 0-10 scale), morphine consumption, and complications were meta-analyzed. Quality of the included studies was assessed using the Cochrane risk-of-bias tool. The authors defined the best choice for postoperative analgesia as the one that had significant difference in pain scores, morphine consumption, and had no significant difference in the risk of complications compared with placebo in the initial 48 postoperative hours.

Results: In total, 66 studies with 4,168 patients were included in this network meta-analysis. Only periarticular infiltration was significantly superior to placebo in pain scores and morphine consumption (pain at 2 hours: mean difference [MD] -0.74, 95% confidence interval [CI] -1.36 to -0.12; pain at 6 hours: MD -0.81, 95% CI -1.42 to -0.21; pain at 12 hours: MD -0.85, 95% CI -1.53 to -0.17; pain at 24 hours: MD -0.80, 95% CI -1.19 to -0.40; morphine consumption at 24 hours: MD -10.12, 95% CI -14.31 to -5.93; morphine consumption at 48 hours: MD -5.62, 95% CI -6.74 to -4.51). Periarticular infiltration did not increase the risk of complications compared with placebo (nausea and vomiting: odds ratio [OR] 0.63, 95% CI 0.34-1.16; pruritus: OR 0.74, 95% CI 0.35-1.58; urinary retention: OR 0.55, 95% CI 0.25-1.23). In addition, There was no significant difference between adductor canal block and femoral nerve block in pain scores and morphine consumption (pain at 2 hours: MD -0.01, 95% CI -1.44 to 1.42; pain at 6 hours: MD 0.29, 95% CI -0.28 to 0.86; pain at 12 hours: MD 0.36, 95% CI -0.44 to 1.16; pain at 24 hours: MD 0.26, 95% CI -0.22 to 0.75; pain at 48 hours: MD -0.36, 95% CI -0.97 to 0.24; morphine at 24 hours: MD 1.04, 95% CI -4.70 to 6.79; morphine at 48 hours: MD -0.32, 95% CI -0.70 to 0.07; postoperative nausea and vomiting: OR 1.07, 95% CI 0.55-2.09; pruritus: OR 1.36, 95% CI 0.66-2.79; urinary retention: OR 1.41, 95% CI 0.37-5.29).

Conclusions: Based on current evidence, most analgesic methods could result in lower pain scores and decrease morphine consumption when compared with placebo; however, differences between methods were small and inconsistent. There seemed to be no significant difference between adductor canal block and femoral nerve block in pain score, morphine consumption and complications.

Level of evidence: Level I, meta-analysis of Level I RCTs.