Femoral nerve block use in anterior cruciate ligament reconstruction surgery

The goal of this study was to determine whether femoral nerve blocks (FNBs) provide patients undergoing anterior cruciate ligament reconstruction greater pain relief or other benefits compared with more standard pain medication regimens.

We searched PubMed, EMBASE, and the Cochrane Database using the following search terms: "ACL or anterior cruciate ligament" and "femoral nerve block or peripheral nerve block" or "regional anesthesia." Thirteen studies were found that fit the inclusion criteria of being randomized controlled trials with a Level of Evidence of I or II, comparing FNB or 3-in-1 blocks with control groups undergoing various multimodal pain regimens.

Only 5 of the 13 studies found a significant difference in pain relief with FNB compared with the control groups; however, the difference in several of the studies may not be clinically relevant. Of the 13 studies, 6 examined parameters other than pain, and only 1 study found a greater incidence of nausea and sedation in its control group. Patient satisfaction was examined in 2 studies, with both finding no difference between groups. Nine studies used a single graft type, and the two studies using multiple graft types accounted for this in their analyses.

On the basis of the available Level I and II data from randomized controlled trials, there appears to be no evidence that FNBs add additional benefit over multimodal analgesia. FNBs have not been shown to significantly affect patient pain, readiness for discharge, or outcome scores. There is a small but identifiable risk associated with performing FNBs, with potentially catastrophic effects.

Level II, systematic review of Level I and II randomized controlled trials with minimal heterogeneity.