Impact of Intra-Articular Local Anesthesia Infiltration versus Femoral Nerve Block for Postoperative Pain Management in Total Knee Arthroplasty

BACKGROUND: Postoperative pain relief after total knee arthroplasty (TKA) can be attained by using several techniques such as intravenous analgesia, epidural analgesia, and peripheral nerve blocks that include femoral nerve and saphenous nerve. Several authors recommended intra-articular injection of local anesthetic (IALA) as a part of multimodal analgesia regimens for TKA instead of other techniques. AIMS: The present study compares IALA technique efficacy with single-shot femoral nerve block (FNB) as part of multimodal analgesia regimen in TKA patients for postoperative pain management. SETTING AND DESIGN: Perioperative care, randomized double-blind comparative study. SUBJECTS AND METHODS: We recruited a total of 60 patients scheduled for unilateral total knee replacement under spinal anesthesia. Subjects were allocated randomly into two groups FNB and IALA receiving ultrasound-guided FNB and Intra-articular local anesthesia and morphine mix infiltration, respectively. Twenty-four hour postoperative morphine consumption through patient-controlled analgesia was the primary outcome measure in our study. Secondary outcome measures were pain scores, nausea and vomiting. STATISTICAL ANALYSIS: Chi-square test, Mann–Whitney test. RESULTS: The amount of morphine consumed at the end of 24 h was noted to be higher in IALA group as compared to FNB (FNB − 16.03 ± 9.37 mgs; IALA − 23.60 ± 13.73 mgs P = 0.03). Visual analog score at 24 h with knee flexion was better in FNB group (FNB − 1.27 ± 1.43; IALA 2.42 ± 2.54, P = 0.04). CONCLUSION: FNB technique provides better analgesia in comparison to IALA for postoperative pain management in terms of PCA morphine consumption.