Anatomical variation of median nerve: cadaveric study in brachial plexus

Median nerve is formed by lateral root from lateral cord and medial root from medial cord of brachial plexus. Formation of median nerve occur in front or lateral to axillary artery in axilla. In the present study we observed anatomical variations of median nerve formation in the brachial plexus. We examined formalin fixed 60 upper limbs from 30 adult cadavers (15 males and 15 females) which were above the age 40 years from the department of Anatomy. All the cadavers were dissected on both sides according to Cunningham's Manual of Practical Anatomy. Normal formation of median nerve by two roots noted in 42 (70.0%) of upper limb specimen. Variation of median nerve formation noted in 18 (30.0%) upper limb specimen. Three roots taking part in the formation of median nerve in 13 (21.7%) upper limb specimen where additional root coming from lateral cord of brachial plexus. Four roots taking part in formation of median nerve in 3 (5.0%) upper limb specimen, where additional roots coming from lateral cord and posterior cord of brachial plexus. Lateral root crossed the axillary artery anteriorly to join with medial root lying medial to axillary artery. The median nerve formed medial to third part of axillary artery. Additional communication with musculocutaneous nerve with median nerve seen in 2 (3.3%) upper limb specimen. Knowledge of such anatomical variations is of interest to the anatomist and clinician alike. Surgeons who perform procedures involving neoplasm or repairing trauma need to be aware of these variations. Median nerve variation may lead to confusions in surgical procedures and axillary brachial plexus nerve block anesthesia.