PATTERNS OF MEDIAN NERVE SENSORY INNERVATION TO THE THUMB AND INDEX FINGER - AN ANATOMIC STUDY

Anatomic dissections were performed on 79 cadaveric hands to elucidate the patterns of median nerve sensory innervation to the thumb and ind ex finger. The most common pattern (type I, 69%) consisted of a radial digital nerve to the thumb and a common digital nerve to the first we b, which subsequently divided into a radial digital nerve to the index and an ulnar digital nerve to the thumb. The least common (type II, 6 %) consisted of a common digital nerve to the thumb and a proper digit al nerve to the radial side of the index finger. A trifurcation patter n (type III, 25%) consisted of three proper digital nerves (radial thu mb, ulnar thumb, and radial index). These findings are at odds with mo st standard textbook descriptions, which depict types II and III most frequently.