A Cadaveric Study to Define the Variant Patterns of Median Nerve Formation

Area of Science:

• Anatomy
• Surgical Anatomy
• Clinical Anatomy

Background:

• The median nerve is vital for upper limb function, innervating forearm muscles, hand muscles, and skin.
• Typically, the median nerve forms from two roots: one from the medial cord and one from the lateral cord.
• Variations in median nerve formation have significant clinical implications for surgical and anesthetic procedures.

Purpose of the Study:

• To investigate the frequency of different median nerve formation patterns.
• To document variations in median nerve origin from the cords of the brachial plexus.
• To highlight the clinical relevance of these anatomical variations for medical practitioners.

Main Methods:

• Dissection of 68 axillae from 34 formalin-fixed cadavers.
• Systematic documentation of the number of roots contributing to median nerve formation in each axilla.
• Comparison of observed patterns with the typically described two-root formation.

Main Results:

• A normal two-root median nerve formation was observed in 44 (64.7%) axillae.
• Variations included single-root formation (2.9%), three-root formation (27.9%), and four-root formation (4.4%).
• The majority of cases (35.3%) exhibited non-typical median nerve formations.

Conclusions:

• The study reveals a high prevalence of anatomical variations in median nerve formation.
• Knowledge of these variations is essential for surgeons and anesthesiologists operating in the axillary region.
• Awareness of aberrant median nerve patterns can help prevent iatrogenic injuries during procedures.