Analgesic efficacy of anterior iliopsoas muscle space block combined with local infiltration analgesia after total hip arthroplasty: A prospective, double-blind, placebo-controlled study

The present study aimed to evaluate the efficacy of ultrasound-guided anterior iliopsoas muscle space block (AIMSB) combined with local infiltration analgesia (LIA) for pain management and recovery in patients who have undergone total hip arthroplasty (THA) via a posterolateral approach. In this prospective, double-blind, placebo-controlled study, 80 patients undergoing primary THA under general anesthesia were included in the final analysis between March 22, 2022, and June 1, 2022. All patients were randomly assigned to receive AIMSB combined with LIA (AIMSB group, n = 40) or sham AIMSB and LIA (Sham group, n = 40). The primary outcome was cumulative morphine consumption (mg) within 24 h after surgery. Secondary outcomes were pain scores on a visual analog scale (VAS) at rest or during motion after surgery, time to first rescue analgesia, cumulative morphine consumption during hospitalization, intraoperative consumption of opioids, postoperative recovery, and postoperative adverse effects. Patients in the AIMSB group consumed significantly less morphine than the Sham group within the first 24 h and throughout hospitalization, as well as smaller amounts of intraoperative opioids. Also, significantly lower pain scores were recorded at rest or during motion within 24 h after surgery in AIMSB patients. Patients in the AIMSB group recovered more quickly than Sham patients. No significant difference was observed in quadriceps strength and postoperative complications between the two groups. Compared to treatment with LIA alone, ultrasound-guided AIMSB combined with LIA can provide better postoperative pain relief, decrease opioid consumption, promote motor sparing, and enhance the recovery of THA patients.