Median nerve thenar motor branch anatomical variations.

BACKGROUND The aim of this study was to determine the prevalence of the different types of median nerve thenar motor branch and to compare them with literature data. MATERIAL AND METHODS This study was conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy of Jagiellonian University Medical College (JUMC) and cadavers from the Department of Forensic Medicine JUMC. The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/ /209/B/2002). RESULTS The studied group comprised 8 (26.7%) women and 22 men (age between 23 and 92 years), yielding a total of 60 thenar motor branches (30 right vs. 30 left). Forty-seven (78.3%) nerves were classified as extraligamentous, 12 (20%) were subligamentous, and 1 (1.7%) was transligamentous. As for the side of origin of the thenar motor branch, in 45 (75%) cases it was the radial side and in 2 (3.33%) cases it was the ulnar side. CONCLUSIONS The obtained results confirm that the extraligamentous type of thenar motor branch is the most common and that the ulnar origin of the thenar motor branch is the rarest.