Previously Unreported Variation in the Innervation of the Psoas Major Muscle

Abstract

Injury to the nerves of the lumbar plexus can result in significant disability. Therefore, the clinician should be knowledgeable of both the normal and variant anatomy of these branches. We report what we believe to be the first description of the accessory obturator nerve providing a branch to the psoas major muscle. Such a variant innervation to the psoas major muscle should be kept in mind by those who examine patients or operate near the lumbar plexus.