Lumbar Plexus Block versus Peri-capsular Injection for Hip Arthroscopy: A Single-Blinded Randomized Controlled Trial

Abstract

Objectives:To perform a single-blinded, randomized controlled trial comparing pericapsular injection versus lumbar plexus blockade for post-operative pain control following arthroscopic surgery on the hip.Methods:70 consecutive patients undergoing hip arthroscopy were prospectively assessed over a six-month period from 2017 to 2018. Patients were randomly allocated to 1 of 2 groups. 35 patients received a lumbar plexus blockade by a single anesthesiologist, while 35 patients received a pericapsular injection of 30cc of ropivacaine and 12mg of morphine. Post-operative pain in the post-anesthesia care unit (PACU) as measured by the numeric rating scale (NRS), time to discharge, PACU morphine equivalents and adverse effects were collected by PACU staff. Post-operative day (POD) 1 and POD 2 narcotic use was obtained through a phone call with the patient on post-operative day 2.Results:We found no statistically significant difference in PACU pain scores at all time-points, although there was a trend towards lower pain for patients receiving a pericapsular injection. PACU and short-term narcotic demand did not differ significantly between the two arms. Time to discharge from the PACU did not differ. There were no major adverse events reported for either intervention.Conclusion:Pericapsular injection provides equivalent analgesia when compared to lumbar plexus injection. It is a safe, time-saving intervention that allows for efficient post-operative analgesia for patients undergoing hip arthroscopy.