A Clinical Evaluation of the Length of Segments and Branches of the Brachial Plexus

The brachial plexus is a network of nerves originating in the periclavicular region and provides sensory and motor innervation to the upper extremity. The plexus is an important structure due to its anatomical location and vulnerability to damage. As such, surgeons need to be able to locate individual plexus segments or nerve branches when performing procedures. However, finding the sites of uniting and dividing points within the brachial plexus can prove challenging.

Dissections were performed bilaterally on 30 formalin-fixed adult cadavers to expose the individual segments and branches of the brachial plexus. Subsequently, various measurements were taken. Measurements included the length of the roots, trunks, divisions, cords, and terminal branches (musculocutaneous, median, ulnar, radial, and axillary nerves).

The statistical test revealed the Mean±SD length of the middle and inferior trunk was 34.75±29.6 mm and 39.8±14.2 mm respectively. The Mean±SD of lateral cord was 47.75±14.98 mm, the posterior cord 45±13.20 mm, and the medial cord was 48.75±16.44 mm. The terminal branches were as follows: Musculocutaneous nerve 67±25.03 mm, median nerve 206.20±116 mm, ulnar nerve 219.70±29.70 mm, radial nerve 117.30±17 mm and axillary nerve 65.60±13.30 mm.

A thorough understanding of all relevant anatomical landmarks is mandatory for any successful procedure. Common techniques, such as brachial plexus blocks, require detailed anatomical literature due to the complexity and variability of the plexus. Results from this study will add to the understanding of the anatomy of the brachial plexus and further assist clinicians in pre- and perioperative surgical planning.