The dorsal branch of the digital nerve: an anatomic study and clinical applications.

The dorsal branch of the digital nerve was studied in 40 fingers from 8 cadavers. Our anatomic dissections showed that the dorsal branch of all digital nerves was constantly present. It arose from the digital nerve at the base of the proximal phalanx where digital vascular bifurcation usually occurred. The dorsal branch crossed the digital vascular bundle posteriorly and lay just above the extensor mechanism deeper to the dorsal-sensitive branches of the ulnar and radial nerves in the proximal and middle part of the proximal phalanx. The dorsal branch of the digital nerve supplies not only the dorsum of the middle phalanx, but also sends a branch to the dorsum of the proximal phalanx. Both dorsal branches should be used for maximal sensation while performing an innervated cross-finger flap. Furthermore, if only one digital nerve anastomosis is performed, a painful neuroma may develop from the unrepaired digital nerve stump. Therefore both of the transected digital nerves should be repaired. The dissections of the dorsal branches may be started proximally from distal palmar crease when any difficulties are encountered for nerve isolation. Nerve stumps of the dorsal branches should be placed in a deeper tissue plane and epineural sutures may be useful to prevent painful neuroma. This technique should be used in selected patients to gain maximal sensibility regarding the described points.