Comparison between local infiltration analgesia with combined femoral and sciatic nerve block for pain management after total knee arthroplasty.

Background: Total knee arthroplasty (TKA) is usually associated with moderate to severe postoperative pain. Peripheral nerve block (PNB) and local infiltration analgesia (LIA) are two major methods for postoperative analgesia. Femoral nerve block (FNB) leads to residual posterior knee pain; thus, currently sciatic nerve block (SNB) and LIA are two major options for supplementing FNB. However, the efficacy and safety of LIA compared with combined femoral and sciatic nerve block still remain controversial. Here, we conducted a study to analyze the postoperative analgesic efficacy of these two methods.

Method: Two hundred six patients undergoing TKA were enrolled in a retrospective cohort study. The patients received either PNB or LIA. All patients in PNB group were conducted combined femoral and sciatic nerve block. All patients were encouraged to use patient-controlled analgesia (PCA) after surgery. The postoperative visual analog scale (VAS) at rest or with movement during the first 24 h and 48 h was recorded. We analyzed the VAS of 24 h, VAS of 48 h, opioid consumption, and adverse effects between PNB group and LIA group. Chi-square test and nonparametric test were used in this study.

Results: There were 82 patients in the PNB group and 124 patients in the LIA group. The patients' characteristics such as age, height, weight, and ASA showed no significant difference (P > 0.05). No significant differences were found (P > 0.05) between the two groups regarding VAS score at rest or with movement. The LIA group had less opioid consumption than the PNB group but without significant difference (P > 0.05). In both groups, the most common side effect was nausea, and the side effects showed no significant differences between groups (P > 0.05).

Conclusion: Local infiltration analgesia provided a similar analgesic effect and complications compared with combined femoral and sciatic nerve block in the short term. Considering less opioid consumption with local infiltration analgesia though without significant difference and its convenience, local infiltration analgesia provided better postoperative analgesia.