Study Summary

Sixty patients with advanced knee osteoarthritis (KOA) undergoing primary total knee arthroplasty (TKA) were randomized to receive combined posterior capsule of the knee (iPACK) plus adductor canal block (ACB) or two-level lumbar–sacral erector spinae plane block (ESPB) at L1 and S1. The primary outcome of interest was total opioid consumption within 48 hours postoperatively, expressed as morphine milligram equivalents (MME). Secondary outcomes included time to first rescue opioid administration, Numerical Rating Scale (NRS) pain scores, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and quadriceps muscle strength. Outcomes were assessed up to 48 hours after surgery at predefined intervals. Overall, the results of the study revealed that the iPACK+ACB group had significantly lower opioid consumption, prolonged time to first rescue analgesia, lower early postoperative pain scores, and reduced inflammatory response compared with the two-level ESPB group, while preserving quadriceps strength in both groups. These findings suggest that iPACK combined with ACB may provide a more effective motor-sparing analgesic strategy for elderly patients undergoing TKA.