Clinical Implications And Embryological Basis Of Median Nerve Variations In Indian Fetuses
DOI:
https://doi.org/10.67440/ahj.v21i5s.1287Keywords:
Median nerve, Upper extremity, Brachial Plexus block, Anatomical variation, Human Fetus, Embryology.Abstract
Introduction:
The median nerve, a critical structure for upper limb function, presents considerable variability in its formation, directly affecting surgical interventions and regional anesthesia. This study investigated anatomical variations in the formation of the median nerve in Indian human fetuses and explored their embryological foundations. Comprehensive knowledge of these variations is essential to prevent iatrogenic nerve injury during clinical procedures.
Methodology:
Twenty-three aborted human fetuses, aged 16–40 weeks of gestation, were obtained from the Department of Obstetrics and Gynaecology, after parental consent. Following preservation in formalin, bilateral dissections of the pectoral, axillary, and arm regions were performed in the Department of Anatomy. The cords of the brachial plexus and associated vessels were exposed, and the formation of the median nerve was documented.
Results:
Anatomical variations in median nerve formation were identified in 21 of 46 upper limbs (45.65%). While a classical two-root "V" formation was observed in 24 limbs (52.17%), the most prevalent variations were three-root formation (19.57%) and low-level formation (13.04%). Less common patterns included communication with the ulnar nerve (4.35%), formation posterior to the axillary or brachial arteries (6.52%), and single lateral cord origin (2.17%). Chi-square analysis indicated no significant association between these variations and gestational age, crown–rump length, gender, side, or plexus fixation pattern (p > 0.05).
Conclusion:
Nearly half of the fetal upper limbs examined displayed variations in median nerve formation. These results suggest that such morphological deviations are a common feature of fetal development, likely arising from early embryological signaling differences in the brachial plexus. Awareness of these patterns is essential for clinicians to minimize iatrogenic injury during nerve blocks and surgical interventions.
