PROSPECTIVE RANDOMIZED STUDY COMPARING SUPRAINGUINAL FASCIA ILIACA BLOCK VERSUS PERICAPSULAR NERVE GROUP BLOCK VERSUS LOCAL ANAESTHETIC INFILTRATION VERSUS SPINAL ANAESTHETIC WITHOUT ADJUNCTS FOR PAIN CONTROL FOLLOWING TOTAL HIP ARTHROPLASTY

Postoperative pain following total hip arthroplasty (THA) leads to increased narcotic consumption, decreased patient satisfaction, delayed mobilization, and prolonged hospital stays.1 Multimodal analgesia has become the standard of care following THA, and can include various regional anesthetic adjuncts such as suprainguinal fascia iliaca compartment block (FICB) and pericapsular nerve group (PENG) block, as well as local anesthetic infiltration (LAI) by the surgeon.2 The most efficacious regional anesthetic adjunct is yet to be determined, with inconsistent evidence on their efficacy and no randomized study directly comparing these three adjuncts to date.3-6 The purpose of this randomized trial was to compare the impact of FICB, PENG block, and LAI on postoperative pain, opioid use, and side effects associated with pain control following primary THA for osteoarthritis. One hundred and thirty-nine patients undergoing primary THA under spinal anesthesia for hip osteoarthritis were randomized to receive FICB (n=35), PENG block (n=35), LAI (n=33), or spinal anesthetic without any adjuncts (control; n=36). The primary outcome was cumulative opioid consumption at 24 hours postoperatively. Cumulative opioid consumption (in mg of morphine-equivalents) was recorded at four, 24, and 48 hours postoperatively. Postoperative pain scores (visual analog pain scale; VAS) were recorded at four hours, immediately before and after the first physiotherapy session, and at two and four days. Finally, patient satisfaction with pain control, length of hospital stay and complications were also recorded. For statistical analysis, group comparisons were performed using two-tailed t-test (alpha = 0.05). All study groups had similar patient demographics, including mean age, gender, BMI. At 24 hours postoperatively, all groups with adjuncts had significantly lower cumulative opioid consumption (FICB = 27.0 mg, LAI = 26.9 mg, PENG = 30.3 mg) compared to the control group (42.7 mg; p=0.003, p=0.004, p=0.016, respectively). FICB group had lower opioid consumption at four hours postoperatively compared to the control group (2.4 mg vs. 5.9 mg; p < 0 .05) while LAI group and PENG block group had similar opioid consumption to the control group. In addition, LAI group had lower pain at 4 hours (VAS = 1.8) compared to the control group (VAS = 3.1; p=0.026). While there was no statistically significant difference in patient satisfaction with postoperative pain management across the study groups, there was a trend toward improved satisfaction for LAI (effect size 0.65, p=0.08). FICB, LAI and PENG block are equally efficacious in reducing opioid consumption for acute postoperative pain, when compared to spinal anesthesia alone. Of note, patients who received LAI had decreased subjective pain at 4 hours and a trend towards better satisfaction with pain control following THA. Because LAI can be performed intra-operatively, without the need for a secondary procedure, this may be the adjunct of choice to improve pain control post-THA.