Extracapsular local infiltration analgesia in hip arthroscopy patients: a randomized, prospective study

Hip arthroscopy patients can experience significant post-operative pain. Many strategies to combat this pain have been explored including nerve blocks, which can be costly. An alternative option for pain management is local infiltration analgesia (LIA) which has been studied in hip and knee arthroplasty, but its ability to decrease pain in the setting of hip arthroscopy remains uncertain. A prospective randomized controlled trial of 74 patients who underwent hip arthroscopy at a single medical center was performed. Thirty-seven patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure while 37 from the control group received no injection. Primary outcome measures were both maximum and discharge numeric rating scale (NRS) pain scores while in the post-anesthesia care unit (PACU). The LIA group had a statistically significant decrease in the maximum PACU NRS score (6.16 versus 7.35, P = 0.009), however this did not reach the level of minimal clinically important difference of 1.5. There was an insignificant difference in discharge PACU pain scores. This is the first randomized controlled trial studying extracapsular LIA in hip arthroscopy. While LIA offers an uncomplicated and low-cost approach to post-operative pain management, this specific technique did not reduce pain to a clinically significant level.