Utilization of Quadratus Lumborum Block for Postoperative Analgesia Following Hip Arthroscopy: A Prospective, Randomized Clinical Trial

The number of hip arthroscopy cases has surged with over a 200% increased experienced between 2007 and 2011]. This increased number of cases is due to both improved techniques and an increased number of indications]. As with most newer operative techniques, the optimal method of perioperative pain control is still emerging and past publications indicate that the majority of patients experience moderate to severe pain postoperative pain. In the wake of a national opioid epidemic, consistent and reliable implementation of non-opioid analgesic strategies is exceedingly important and regional anesthesia often plays a key role in postoperative pain management.

Although quadratus lumborum blocks were first described in 2007 as an truncal block, numerous publications have recently highlighted its effectiveness as an analgesic technique for hip fracture and hip arthroplasty and possibly the ideal regional technique for hip arthroscopy. Unfortunately, prospective randomized studies are lacking. This prospective study would randomize patient to receive or not receive a quadratus plane block prior to surgery. The primary end point would be opioid consumption in the postoperative anesthesia care unit. Our hypothesis is that quadratus lumborum blocks will decrease postoperative opioid consumption.

The quadratus lumborum blocks is fascial plane block. Originally described for abdominal surgery, numerous case reports and editorial publications have highlighted the effectiveness of quadratus lumborum blocks as an analgesic technique for hip fracture and hip arthroplasty and possibly the ideal regional technique for hip arthroscopy. Unfortunately, prospective randomized studies are lacking.

The quadratus lumborum block is performed by injecting local anesthetic deep to the transversus abdominus abdominus apnoneurosis and superficial to the fascia transversalis with direct ultrasound guidance. After completing consent, placing monitors and providing mild sedation, the patient is positioned laterally and the muscular anatomy (external oblique, internal oblique, transverse abdominis, quadratus lumborum and latissimus dorsi muscles) identified. After placing a subcutaneous skin wheel with lidiocaine, a blunt regional anesthesia needle is inserted using in-plane ultrasound guidance. Local anesthetic is deposited incrementally with frequent aspiration in the anterolateral border of the quadratus lumborum muscle at the junction of the transversalis fascia, outside the anterior layer of the thoracolumbar fascia and superficial to the fascia transversalis.

Risks of the quadratus lumborum block are similar to most truncal blocks and include infection, bleeding, bowel perforation or local anesthethetic toxicity (LAST). Infection risk is minimized by utilizing appropriate antiseptic and sterile technique as is standard for any regional procedure. Risk of a retroperitoneal hematoma is increased with the deep (QL3) approach to the quadratus lumborum block because of its transmuscular approach and likelihood of abdominal branches of lumbar arteries in the path of the needle. For this reason, this (QL3) approach to the quadratus lumborum block will not be used for this study. The risk of LAST is a risk with any regional procedure and is minimized by frequent aspiration, incremental local anesthetic injection and vital signs monitoring throughout.