One hundred twenty patients with end-stage knee osteoarthritis scheduled for primary TKA were randomized 1:1 to imrecoxib added to conventional care (n=60) or conventional care alone (n=60). The primary outcome was pain (VAS at 6, 12, 24, 48 h). Secondary outcomes included knee ROM at 24/48 h, in-hospital opioid consumption (tablets), inflammatory markers (ESR, CRP, IL-6) at 24/48 h, and adverse events. Outcomes were assessed up to 48 h after surgery, with opioid tablets tallied at discharge. Overall, the results showed lower VAS at rest (24 h, 48 h) and during movement (all timepoints) with imrecoxib, greater ROM at 24/48 h, and markedly reduced opioid use; inflammatory markers (ESR, CRP) were modestly lower at 48 h, and adverse events were similar between groups. In short, adding imrecoxib improved early analgesia and function while sparing opioids, without increasing adverse events.