The cutaneous innervation of the dorsal hand: detailed anatomy with clinical implications

PURPOSE: Detailed knowledge of the anatomy of the cutaneous innervation to the dorsal surface of the hand is valuable information. Because surgical access to the wrist often is obtained via the dorsal skin it would be helpful particularly to delineate an area where surgical incisions would not injure underlying nerves. METHODS: Thirty cadaver forearms were dissected carefully to examine in detail the anatomy of the lateral antebrachial cutaneous nerve, the superficial branch of the radial nerve, and the dorsal branch of the ulnar nerve. Each hand then was evaluated for an area free of any major nerve branches over the dorsal wrist. RESULTS: Although the innervation to the dorsal hand varies certain patterns exist. The innervation pattern between the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve is distributed evenly, dual innervation is frequent between the 2 nerves, and the lateral antebrachial cutaneous nerve is a common contributor to the innervation of the thumb. The superficial branch of the radial nerve and the dorsal branch of the ulnar nerve have identifiable branching patterns and have been classified according to a system developed for this study. CONCLUSIONS: Two classification systems based on detailed dorsal hand cutaneous innervation patterns can be used to specify the placement of a safe dorsal skin incision away from major nerve branches.