One hundred fifty-nine patients with knee arthroplasty were randomized to receive either perineural betamethasone (n=53), intravenous betamethasone (n=47), or normal saline (n=49). The primary outcome of interest was the numeric rating scale (NRS) score for pain during a 6-meter walk test at 24 hours post-surgery. Secondary outcomes included NRS scores at rest and during activity at various postoperative intervals, range of motion (ROM), and levels of inflammatory markers (IL-1β, TNF-α, HS-CRP). Outcomes were assessed up to 72 hours post-surgery. Overall, the results of the study revealed that both perineural and intravenous betamethasone significantly reduced pain and inflammation, and improved ROM compared to the saline group. These findings suggest that betamethasone, administered either perineurally or intravenously, enhances early postoperative recovery in knee arthroplasty patients.