Branching of the medial palmar nerve in an equine. case report

Abstract

The equine palmar nerves are the strongest in the manus and the most commonly used in perineural
anesthesia, both for diagnostic and therapeutic purposes. The medial palmar nerve is formed from the
medial terminal branch of the median nerve. The lateral palmar nerve is formed from the union of the lateral
terminal branch of the median nerve and the superficial palmar branch of the ulnar nerve. Both nerves run
along the palmar surface of the third metacarpal bone, exchanging fibers between them by means of a
communicating branch. Both palmar nerves continue as digital nerves. A cadaveric piece corresponding to
the left hand of an adult equine was dissected. The medial palmar nerve was observed giving off a branch
at mid-height of its course. The branch is located parallel to the communicating branch and crosses laterally.
It then turns distally, superficial to the lateral border of the digital flexor tendons. The branch ends in
relation to an anastomotic branch of the palmar digital veins II and III. Although anatomical variants do not
usually affect function and cannot be considered pathological, they can represent a challenge in the
application of the perineural anesthesia technique.