Comparative effects of intracapsular corticosteroid injection on pain control after total hip arthroplasty: a prospective, randomized controlled trial.

Effective pain control after total hip arthroplasty (THA) is essential for postoperative recovery; however, limited data exist comparing different corticosteroid agents using a three-arm design that includes a saline control, administered as a single-site intracapsular injection with extended postoperative assessment. This prospective, single-center, randomized controlled trial compared the analgesic effects of two intracapsular corticosteroids with saline. One hundred fifty patients undergoing primary THA were randomized to receive an injection into the hip joint capsule at wound closure with triamcinolone acetonide plus bupivacaine, betamethasone plus bupivacaine, or saline. After protocol deviations, 138 patients were included in the final analysis. Postoperative pain was assessed using the visual analog scale (VAS) at rest and during motion on postoperative days 3, 5, and 7. Baseline demographics and perioperative variables were comparable among groups. At rest, triamcinolone acetonide resulted in significantly lower VAS scores than saline across all assessment points. During motion, both corticosteroid groups demonstrated a significantly higher proportion of patients achieving sufficient pain control on postoperative day 3 compared with saline. Rescue analgesic use and frequency were significantly reduced in the corticosteroid groups. No major injection-related complications were observed. These findings indicate differential analgesic effects among corticosteroid agents and suggest that triamcinolone acetonide provides more effective postoperative pain control after THA.