The Role of Nerve Blocks in Hip Arthroscopy

The popularity of arthroscopic hip surgery has increased greatly over the last 10 years, particularly for correcting Femoroacetabular Impingement (FAI). FAI is a structural abnormality of the proximal femur, the acetabulum, or both. It is a leading cause of labral tears in the hip joint and can cause cartilage damage, which may increase subsequent risk of developing osteoarthritis. Though far less invasive than open hip surgery such as for a total hip replacement, hip arthroscopy can cause significant postoperative pain for the patient. Given how relatively new the procedure still is, methods of pain control are highly variable. Peripheral nerve blocks, mainly femoral nerve and lumbar plexus blocks, have been used by some surgeons to control postoperative pain. However, in addition to their sensory effects, these blocks cause motor impairment that has been associated with a significantly higher risk of falling.

In managing pain after any operation, opioid consumption is, of course, a significant concern. Ideally, hip arthroscopy patients could receive a peripheral nerve block that decreases pain and the need for opioids, but without the muscular weakness and increased fall risk observed with femoral nerve and lumbar plexus blocks. This may be achievable with the newer Quadratus Lumborum (QL) block.

The ultrasound-guided QL block is currently most commonly used for abdominal surgery.

However, several case studies of a single-injection QL block in hip replacement surgeries have been successful in minimizing pain and opioid use while sparing motor function and avoiding the muscle weakness that can lead to falls. In the approach utilized in these cases, local anesthetic was injected at the anterolateral border of the QL muscle to achieve analgesia ranging from the T6-T10 through L3 dermatomes. One group has anecdotally reported great success in using these QL blocks for alleviating postoperative pain with hip arthroscopy, but no studies to date have evaluated the effectiveness of QL blocks for arthroscopic hip surgery.

This study is a randomized, controlled, double-blind trial. Patients undergoing hip arthroscopy who agree to participate will be randomly selected to receive an ultrasound-guided QL block with either local anesthetic (QL block group) or normal saline (control group) preoperatively.