Use of Nerve Stimulation During Adductor Canal Block Could Help Identify and Avoid Injury to Nerve to Vastus Medialis

A study using lower limbs from two cadavers to demonstrate the technique of adductor canal (AC) block found that the needle trajectory of the traditional approach led to impalement of the nerve to vastus medialis (NVM) in 33% of cases and direct contact with the nerve in another 22%. The AC block is a common technique for pain relief after lower limb surgery. This block intentionally targets the saphenous nerve, though another important target for pain control is the nearby nerve to vastus medialis. The AC block is traditionally performed by depositing local anesthetic next to the femoral artery, but the NVM potentially lies in the trajectory of the needle path.

The study, “Subsartorial Approach to the Adductor Canal and the Risk of Injury to the Nerve to Vastus Medialis,” conducted at Duke University Medical Center in Durham, NC, aimed to determine whether the traditional approach to AC block puts the NVM at risk of injury. Awarded one of three Best of Meeting Abstracts, it will be presented at a session on Friday, April 21, 10:15 am, at the 48th Annual Regional Anesthesiology and Acute Pain Medicine Meeting at The Diplomat Beach Resort in Hollywood, FL.

“While we cannot guarantee that NVM contact would have resulted in long-term nerve dysfunction, it is generally accepted that needle-nerve contact should be avoided in order to minimize lasting injury,” stated Emily Barney Hall, MD, lead author. “Based on these findings, we recommend utilizing nerve stimulation to help with the identification of NVM, as doctors can feel the contraction of vastus medialis muscle as confirmation of nerve location. This technique, in addition to ultrasound guidance, may help prevent possible NVM injury during this common procedure.” Co-authors of the study are Drs. Maggie Holtz, Jeff Gonzales, Mark Hamilton, Gary Schwartz, Roy Winston, and Jeff Gadsden.

ASRA Pain Medicine is a membership society of more than 5,000 healthcare professionals devoted to advancing evidence-based practice of pain medicine across the pain continuum, from acute pain to chronic pain. Our mission is to advance the science and practice of regional anesthesia and pain medicine to improve patient outcomes through research, education, and advocacy. Our vision is to relieve the global burden of pain. We are committed to integrity, innovation, inclusiveness, service, compassion, and wellness. Learn more at www.asra.com.