Efficacy of Adductor Canal Block Combined With Additional Analgesic Methods for Postoperative Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

Abstract

Background: The aim of this study is to evaluate the efficacy of adductor canal block (ACB) combined with additional analgesic methods in total knee arthroplasty (TKA) and investigate whether blocking the sensory nerves that are distributed in the posterior and lateral aspect of knee could improve postoperative pain control.

Methods: Two hundred scheduled patients for TKA were randomly allocated into 4 groups: Group A received ACB combined with iPACK (interspace between the popliteal artery and capsule of the knee) block and lateral femoral cutaneous nerve block (LFCNB); Group B received ACB combined with iPACK block; Group C received ACB combined with LFCNB; and Group D received ACB only. Postoperative pain score was the main primary outcome. Secondary outcomes included the morphine consumption and analgesic duration. Other outcomes included knee range of motion, quadriceps strength, ambulation, Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index physical function, timed up and go (TUG) test, and complications.

Results: Groups A, B, and C had lower postoperative pain scores within 12 hours at rest and 8 hours with activity than Group D (P < .05). In addition, Group A had lower morphine consumption than both Group C (P < .05) and Group D (P < .01). Group A had the longest analgesic duration (19.21 ± 3.22 hours) among all groups. There were no significant differences among the groups in terms of mobility and complication after surgery.

Conclusion: Combining ACB with both iPACK and LFCNB is an effective method for decreasing early postoperative pain in TKA without increasing the complications or affecting the early rehabilitation.

Keywords: adductor canal block; analgesia; iPACK; lateral femoral cutaneous nerve block; total knee arthroplasty.