Efficacy of adding infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) to adductor canal block and local infiltration analgesia in total knee arthroplasty: A retrospective cohort study.

Objective: Local infiltration analgesia (LIA), adductor canal block (ACB), and infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) are popular multimodal analgesia techniques used during total knee arthroplasty (TKA). This study aimed to explore the efficacy of adding the IPACK technique to ACB and LIA in patients undergoing TKA.

Methods: In this retrospective cohort study, patients who underwent primary unilateral TKA were divided into two groups based on their date of admission. Sixty-three patients underwent IPACK, ACB and LIA (IPACK group) during surgery, while 60 patients underwent ACB and LIA (control group). The primary outcome was the postoperative administration of morphine hydrochloride as a rescue analgesic. Secondary outcomes included time to first rescue analgesia, postoperative pain assessed using the visual analog scale (VAS), functional recovery assessed by knee range of motion and ambulation distance, time until hospital discharge, and complication rates.

Results: The two groups were similar in average postoperative 0-to-24-h morphine consumption (11.8 mg for the control group vs 12.7 mg for the IPACK group, p = .428) and average total morphine consumption (18.2 mg vs 18.0 mg, p = .983) during hospitalization. There were also no significant differences in the secondary outcomes.

Conclusions: The addition of IPACK to ACB and LIA did not provide any clinical analgesic benefits. Orthopedic surgeons and anesthesiologists are justified in using ACB and LIA without IPACK for TKA.