Nerve transfers in the arm and elbow are devised to restore arm and elbow function through reinnervation of target muscles. The available nerve transfers for the arm and elbow are procedures to restore elbow flexion/extension. The principle nerves that are targeted for reinnervation are the musculocutaneous nerve for elbow flexion and triceps brachii branch of the radial nerve for elbow extension. Motor nerve transfers are time sensitive due to muscle atrophy and loss of motor end-plates.
Procedures – Restoration of Arm and Elbow Function
Title: Double Fascicular Nerve Transfer – Median/Ulnar Fascicles to Biceps/Brachialis Branches.
Published: 4/11/2011, Updated: 4/11/2011.
Author(s): Susan E. Mackinnon MD, Andrew Yee BS.
Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO.
The double fascicular transfer is the choice nerve transfer of our institution for musculocutaneous nerve palsies. In cases that involve an unusual direct injury to the musculocutaneous nerve and a site of injury close to target, a direct nerve repair or nerve graft is the more appropriate surgical intervention. The double fascicular transfer utilizes nerve fascicules to the flexor digitorum superficialis/flexor carpi radialis of the median nerve and the flexor carpi ulnaris of the ulnar nerve to reinnervate the biceps brachii and brachialis muscles. This procedure was established by the senior author as a modification of the single fascicular Oberlin transfer to include the brachialis muscle as a target for reinnervation in addition to the biceps brachii muscle. At our institution, the double fascicular transfer has proven to be an excellent procedure for recovering musculocutaneous nerve function by utilizing two donor nerve fascicles, flexor digitorum superficialis/flexor carpi radialis and flexor carpi ulnaris, to reinnervate two targets, biceps brachii and brachialis.
Figure 1 – Identifying Locations of Neurolysis on the Median and Ulnar Nerve By first isolating the recipient biceps brachii and brachialis branches, the branches can be mobilized to determine the appropriate donor nerves and the locations of neurolysis for a tension-free repair . This image demonstrates median nerve (flexor digitorum superficialis/flexor carpi radialis fascicle) as an appropriate donor nerve for biceps brachii, and the ulnar nerve (flexor carpi ulnaris fascicle) for brachialis. This step will prevent unnecessary intraneurolysis when isolating the donor fascicles. Superficial cutaneous nerves are protected to reach this exposure.
Figure 2 – Isolating the Donor Median and Ulnar Nerve Fascicles. The flexor digitorum superficialis / flexor carpi radialis (FDS/FCR) fascicle is found on the ulnar aspect of the median nerve. The flexor carpi ulnaris (FCU) fascicle is found on the radial aspect of the ulnar nerve. Intraoperative stimulation is used to confirm the appropriate donor nerve function, as well as the remaining intact median and ulnar nerve function.
Figure 3 – Double Fascicle Nerve Transfer. The double fascicular nerve transfer restores elbow flexion by reinnervating both the biceps brachii and brachialis muscles. The flexor digitorum superificalis / flexor carpi radialis (FDS/FCR) fascicle of the median nerve is used to reinnervate the biceps brachii. The flexor carpi ulnaris (FCU) fascicle of ulnar nerve is used to reinnervate the brachialis. The donor nerves may reinnervate either recipient nerve for a tension-free repair.