ACB With S-ESPB Versus ACB With iPACK for Knee Arthroplasty

This study will compare two regional anesthesia strategies for pain management after total knee arthroplasty in adults. Both strategies use an adductor canal block (ACB) to provide analgesia while preserving quadriceps muscle strength. The ACB is then combined with either a sacral erector spinae plane block (S-ESPB) or an iPACK (infiltration between the popliteal artery and the posterior capsule of the knee) block to improve posterior knee analgesia. All patients will receive an ultrasound-guided adductor canal block with 20 mL of 0.2% ropivacaine. They will then be randomly assigned to one of two groups: Group 1: ACB combined with a sacral erector spinae plane block (S-ESPB) using 20 mL of 0.2% ropivacaine. Group 2: ACB combined with an iPACK block using 20 mL of 0.2% ropivacaine. Both techniques aim to provide effective postoperative analgesia while minimizing motor blockade and allowing for early mobilization. It is not known whether combining ACB with S-ESPB or with iPACK provides superior pain control, reduces opioid requirements, or results in better functional recovery after total knee arthroplasty. The main purpose of this study is to compare the time to first rescue analgesia and overall postoperative pain control between the two regional anesthesia strategies. The study will also evaluate opioid consumption, motor function, functional mobility, side effects, and block-related complications. We hypothesize that both combinations will provide effective analgesia, but their impact on pain intensity, duration of analgesia, and functional recovery may differ.