A Comparative Study Between Ultrasound-Guided Genicular Nerve Block Combined With Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee Block versus Adductor Canal Block in Total Knee Replacement.

Background: Total knee arthroplasty (TKA) is a surgical intervention that relieves patients experiencing severe pain and joint dysfunction. Objective: The aim is to evaluate ultrasound-guided genicular nerve block (GNB) paired with infiltration between the popliteal artery and the capsule of the posterior knee IPACK block in comparison with adductor canal block (ACB) regarding the analgesia effectiveness and postoperative functional outcomes and rehabilitation parameters for TKA. Methods: This randomized controlled trial enrolled 50 individuals of both genders with American Society of Anesthesiologists Class I-III, planned for TKA with spinal anesthesia. The patients were randomly allocated into two groups of 25 each. Group A underwent an ultrasound-guided GNB combined with an IPACK block, while Group B received an ACB. The amount of morphine consumed postoperatively during the initial 48 h was the main outcome. Additional outcomes encompassed postoperative knee range of motion (ROM), straight leg raising (SLR), and time up and go (TUG) test. Results: Group A patients exhibited significantly lower pain perception scores at 6 and 12 h (p < 0.001) and lower 48 h morphine dose in comparison to Group B (p < 0.001). Group A had significantly better results in ROM and TUG tests on the first and second days (p < 0.001). No significant difference was observed in patients achieving SLR on Day 1 (p=0.999). Overall, Group A had a faster recovery regarding ROM and TUG and better SLR by Day 2. Group A had better satisfaction. Conclusions: In TKA, combined IPACK and GNB offer superior postoperative analgesia, reduced opioid use, and improved functional outcomes compared to ACB. Trial Registration: ClinicalTrials.gov identifier: NCT06423339.