Comparison of the Effect on Postoperative Pain between the Interspace between the Popliteal Artery and the Capsule of the Knee Block, and Local Infiltration Anesthesia, in Combination with Femoral Nerve Block, after Total Knee Arthroplasty

Abstract

Background: The interspace between the popliteal artery and the capsule of the knee (IPACK) block is useful for analgesia after total knee arthroplasty (TKA) in the posterior compartment of the knee without compromising foot strength. Aims: This study was conducted to determine whether the IPACK block, in combination with femoral nerve block (FNB), improves the analgesia provided by local infiltration analgesia (LIA) with FNB. Study Design: Prospective, randomized, open-label trial Place and Duration of Study: Department of Anesthesia, Nagasaki Rosai Hospital, Sasebo, Japan, from April 2020 to November 2021. Methodology: Fifty patients who underwent TKA under total intravenous propofol anesthesia were studied. All patients underwent ultrasound-guided FNB with 30 mL of 0.25% levobupivacaine before the operation. In addition, 250 μg of fentanyl was intravenously administered at the beginning of surgery and before the end of surgery, and 1000 mg of acetaminophen was intravenously administered before the end of surgery. Patients were randomly allocated to one of two groups: Group I (n = 25), which received local infiltration anesthesia with 30 mL of 0.25% levobupivacaine into the posterior capsule of the knee before cementing and Group B (n = 25), which received an ultrasound-guided IPACK block with 30 mL of 0.25% levobupivacaine immediately after the FNB. Patients were administered 1000 mg of acetaminophen or 15 mg of pentazocine as rescue analgesics, if needed. The primary outcome was postoperative pain evaluated by the nursing staff using a numerical rating scale (NRS) at 0, 1, 3, 6, 12, and 24 h postoperatively. Results: No significant differences in patient characteristics and NRS scores were observed between the groups. In addition, no significant differences in the frequency of rescue analgesic use were observed between the groups during the study period. Conclusion: The study concluded that IPACK with FNB and LIA with FNB have an equivalent analgesic effect after TKA.