Anomalous Median Nerve Innervation of the Adductor Pollicis: A Cadaveric Observation

The adductor pollicis is classically supplied by the deep branch of the ulnar nerve. Rarely, anomalous innervation by the median nerve has been reported, with potential implications for carpal tunnel surgery, nerve repair, and anatomical teaching. A descriptive cadaveric prevalence report was conducted on 60 upper limb specimens from 30 cadavers over three academic years. Specimens with prior trauma, surgery, or deformity were excluded. Standard palmar incisions were made, the flexor retinaculum divided, and muscular branches of the median nerve traced following Cunningham’s Manual of Practical Anatomy . Observations were documented and photographed. Ethical clearance was obtained from the institutional review board, and all procedures complied with body donation regulations. Median nerve supply to the adductor pollicis was identified in one specimen (1.67%), confined to the left side. All other specimens demonstrated the classical ulnar innervation. The anomalous branch originated within the carpal tunnel. Median nerve contribution to the adductor pollicis represents a rare anatomical variation. Although observed in only one specimen, awareness of such anomalies is important for surgical safety in carpal tunnel release and nerve repair, and for educational emphasis on variability in peripheral nerve supply. Ontogenetic and phylogenetic perspectives suggest that such variations may reflect persistence of early developmental branches or ancestral innervation patterns.