Infiltration of local anesthetic in the Interspace between the popliteal artery and capsule of the posterior knee "IPACK block" versus adductor canal block "ACB" for pain relief after open wedge high tibial osteotomy: a randomized clinical trial.

Abstract

Background: A high tibial osteotomy is usually associated with severe postoperative pain. Both adductor canal block (ACB) and interspace between the popliteal artery and capsule of the posterior knee (IPACK) have been described as effective block techniques for providing analgesia after knee surgeries, with few comparisons in wedge osteotomy cases. We aim to compare the postoperative analgesic profile of the previously mentioned two block techniques in patients undergoing tibial osteotomies.

Methods: Sixty patients were enrolled in this randomized prospective trial (30 received IPACK and 30 received ACB). Both blocks were installed before the spinal anesthesia after infiltration of 2 mL lidocaine 2%. Twenty mL of bupivacaine 0.25% mixed with dexamethasone as anesthetic adjuvant were used for both blocks. The postoperative analgesic profiles were compared between the two groups.

Results: Postoperative pain scores were lower in the IPACK group, and that decrease was evident throughout the first 10 hours postoperatively. Additionally, the duration of analgesia was much prolonged with the same block (487.50±82.39 vs. 301.93±92.06 minutes with ACB). There was a significant decline in postoperative analgesic consumption (1.27±0.45 vs. 1.8±0.61 gm, P=0.000), and a significant increase in the ambulation distance (19.10±0.60 vs. 17.73±0.45 m, P=0.000) with a significant decline in the duration of hospitalization (43.27±7.61 vs. 54±8.35 hours) in the IPACK group compared to the ACB group.

Conclusions: IPACK is a superior block technique compared to ACB in patients undergoing high tibial osteotomy regarding postoperative analgesia, ambulation distance, and patient satisfaction with little rate of adverse events in both groups.