Anatomical Variations of the Median Nerve: A Cadaveric Study

Abstract

Objectives: Variations in the morphological anatomy of the median nerve such as formation, distribution, and communication have been well documented. All these variations should be taken into account when practicing any surgical approach for the treatment of injuries affecting the median nerve. Furthermore, they are of the utmost importance for interpretation of the clinical presentation.

Methods: The objective of this investigation was to determine the anatomical variations in the formation of the median nerve in cadavers at the Forensic Pathology department in Central Clinical Hospital of the Academy of Sciences of the Russian Federation between January 2022 and April 2022. A descriptive, cross-sectional, and prospective information source study was conducted on 42 anatomical bodies (corpses) and 84 brachial plexuses.

Results: After analyzing the results obtained in this investigation, we concluded that the median nerve presented variation in its formation in 22.6% of the investigated cases. These variations were more common in males (81.8%) than females (18.2%). The anatomical variation was unilateral in 7.1% and bilateral in 19% of all anatomical bodies examined.

Conclusions: The median nerve presented a great number of variations in its formation in roughly 23% of the anatomical bodies, with male being the predominant gender. Furthermore, the most frequent region of formation was the axillary region (92.9%). For clinicians, it is important to remember these variations during surgical procedures in this area and during brachial plexus block.

Keywords: anatomical variations; brachial plexus; corpses; median nerve; peripheral nerves.

Figure 1

Anterior-inferior view right shoulder: axillary artery (1), axillary vein (2), medial root to the median nerve (3), musculocutaneous nerve (4), median nerve (5), and axillary artery (6).

Figure 2

Anterior view, right shoulder: axillary nerve (1), musculocutaneous nerves (2), lateral and medial roots of the median nerve (3,4), median nerve (5), axillary artery (6), thoracodorsal nerve (7), and axillary vein (8).

Figure 3

Anterior-superior view, left shoulder: axillary vein (1), axillary artery (2), lateral cord (3), medial cord (4), deltoid muscle (5), cephalic vein (6), lateral root to the median nerve (7), musculocutaneous nerve (8), anastomotic branch (9), and pectoralis minor muscle (10).