A Randomized Controlled Trial to Evaluate the Analgesic Effectiveness of Periarticular Injections and Pericapsular Nerve Group Block for Patients Undergoing Total Hip Arthroplasty.

Pericapsular nerve group (PENG) block and periarticular injection (PAI) provide motor-sparing analgesia following hip surgery. We hypothesized that PAI offers non-inferior pain relief compared with PENG block in patients undergoing primary total hip arthroplasty (THA). In this randomized trial, 66 patients who underwent primary THA under spinal anesthesia were assigned to the PENG or PAI groups. The primary endpoint was the resting pain score 24 h postoperatively. The secondary endpoints included pain scores at rest and during movement at 6 and 48 h postoperatively, quadriceps strength at 24 h postoperatively, and opioid consumption at 24 and 48 h postoperatively. The mean difference in pain scores at rest between the two groups was 0.30 (95% confidence interval [CI], -0.78 to 1.39) at 24 h postoperatively. The upper 95% CI was lower than the non-inferiority margin, indicating non-inferior performance. No significant between-group differences were observed in the pain scores at 6 and 48 h postoperatively. Additionally, no significant differences in quadriceps strength and opioid consumption were observed between the two groups. The PAI and PENG blocks provided comparable postoperative analgesia during the first 48 h after primary THA. Further investigation is required to determine the optimal PAI technique and local anesthetic mixture.