Retrospective Comparison of Quadratus Lumborum and Pericapsular Nerve Group Blocks for Postoperative Pain Management of Patients Undergoing Outpatient Hip Arthroscopy.

Introduction: Hip arthroscopy is commonly performed as an outpatient procedure and effective postoperative pain management is important to provide quality patient care and enable timely discharge. Multiple regional nerve blocks have been described for pain relief after hip arthroscopy, but there is no consensus on the optimal technique. This retrospective investigation aimed to compare quadratus lumborum (QL) and pericapsular nerve group (PENG) blocks to determine if there are differences in analgesic outcomes after outpatient hip arthroscopy.

Methods: A total of 50 consecutive patients that received QL block and 50 that received PENG block for outpatient hip arthroscopy were identified and compared to determine if there were any differences in the primary outcome of total perioperative opioid consumption prior to discharge from the surgery center. Important secondary analgesic outcomes include postoperative opioid consumption, verbal rating scale (VRS) pain scores or total time in the recovery area. Summary statistics of relevant variables are compared and reported between study groups (QL versus PENG).

Results: For QL and PENG groups, no significant differences were observed in total perioperative oral morphine equivalents (OME) (69.5 vs 60mg; p=0.40), postoperative OME (15 vs 15.3mg; p=0.96) or maximum pain scores in the recovery area (7.0 vs 6.0; p=0.41). Postoperatively, QL block patients were in PACU for a greater length of time after surgery than PENG block patients (89.5 vs 72 minutes; p<0.001). No patients had uncontrolled pain requiring emergency room visits or hospital admission within 24 hours. No neurologic complications or instances of motor weakness were reported after QL or PENG blocks.

Conclusion: This retrospective study observed similar opioid requirements and pain scores for patients receiving QL versus PENG block for hip arthroscopy, though PENG block patients had shorter times in the recovery area. Prospective, controlled trials are required to further explore and confirm these findings.