Sixty-four patients with primary knee osteoarthritis undergoing unilateral TKA were randomized to receive a standardized PAI (n=34) or placebo saline injection (n=30), with all patients receiving combined spinal–epidural anesthesia including ITM and a multimodal analgesia pathway. The primary outcome was postoperative opioid consumption in morphine milligram equivalents (MME) at 0–24 h, 24–48 h, and cumulatively to 48 h. Secondary observations included between-group differences across these time windows and balance of baseline demographics. Outcomes were assessed through 48 hours using medication administration records converted to MME. Overall, the results showed no significant reduction in opioid consumption with PAI versus placebo at 0–24 h (58.87 vs 70.57 MME; p=0.308), 24–48 h (66.50 vs 69.72 MME; p=0.819), or total 0–48 h (125.49 vs 138.80 MME; p=0.556). In brief, within a regimen that already includes ITM, adding PAI did not lower early postoperative opioid requirements.