Study Summary

Two hundred thirty-four patients with severe knee osteoarthritis (KOA) undergoing unilateral total knee arthroplasty (TKA) were randomized to receive periarticular infiltration analgesia (PIA) with 21 mg betamethasone, PIA with 7 mg betamethasone, or PIA without corticosteroid. The primary outcome of interest was Visual Analog Scale (VAS) pain during active knee flexion. Secondary outcomes included resting VAS scores, active range of motion (ROM), 1-minute walking distance, knee circumference, rescue analgesic consumption, serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fasting blood glucose. Outcomes were assessed from 6 hours postoperatively through postoperative day 7. Overall, the results of the study revealed no significant differences in postoperative pain during active knee flexion or ambulation among the three groups. However, corticosteroid-containing PIA improved early ROM, reduced inflammatory markers, and decreased rescue analgesic use, particularly in the high-dose group; although it was associated with transient postoperative hyperglycemia. The findings suggest that adding corticosteroids to PIA may provide functional and anti-inflammatory benefits after TKA, but without meaningful short-term analgesic improvement.