Eighty patients undergoing primary unilateral total hip arthroplasty for osteoarthritis, osteonecrosis of the femoral head, or developmental dysplasia of the hip were randomized to receive anterior iliopsoas muscle space block (AIMSB) combined with local infiltration analgesia (LIA) (n=40) or sham AIMSB with LIA (n=40). The primary outcome was cumulative morphine consumption within 24 hours after surgery. Secondary outcomes included pain scores at rest and during motion, time to first rescue analgesia, total morphine and intraoperative opioid use, postoperative recovery milestones, quality of recovery, quadriceps strength, and adverse effects. Outcomes were assessed up to two postoperative days. Overall, the AIMSB group had significantly lower opioid requirements, lower pain scores within the first 24 hours, faster recovery (earlier ambulation and discharge), and improved quality-of-recovery scores without motor weakness or increased complications. The findings suggest that AIMSB combined with LIA provides superior pain control and enhances recovery compared with LIA alone.