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Figure 2. Transfer between the motor branch of the abductor digiti quinti (ADQMB) and the thenar branch of the median nerve. This
branch is released proximally for 2/3 cm and coapted end to end towards the ADQMB branch

Reinnervation of the muscles of the thenar eminence by direct nerve repair is impossible in high median
nerve injuries, due to the long distance that the nerves have to traverse for regeneration. Nerve transfers
[13]
involving the ulnar (third lumbrical motor branch) and radial nerve (motor branch to the extensor
digiti minimi and extensor carpi ulnaris) have been proposed, but until a few years ago, results were still
[14]
[4]
ambiguous and consequently, classical tendon transfers were preferred . Bertelli et al. recently described
promising results after nerve transfer between the motor branch of the abductor digiti quinti (ADQMB)
and the TBMN in which the ADQMB is dissected as distally as achievable, and then coapted to the TBMN
[14]
without nerve grafting [Figure 2].

Anterior interosseous nerve to median recurrent motor branch transfer: technique
The surgeon opens the carpal tunnel to identify the median nerve and follows it to the origin of the TBMN,
close to the thenar eminence. In the distal forearm, the flexor digitorum superficialis and profundus are
retracted to expose the pronator quadratus and the median nerve. The AIN and the nerve branch to the
pronator quadratus are identified. The pronator quadratus is then dissected superior to the median nerve
with intramuscular dissection to obtain the maximum length.

An interpositional nerve graft (frequently the sural nerve or medial antebrachial cutaneous) is usually
necessary for tensionless suture. Range of motion of the wrist should be assessed before utilizing the graft
to ensure that hand movement will not generate excessive stress on the coaptation.

Abductor digiti quinti motor branch to the recurrent motor branch transfer: technique
A lazy S incision is made on the lateral margin of the hypothenar region, Guyon’s canal is opened, and
the motor branch of the ulnar nerve is identified and followed distally. The branch for the abductor digiti
minimi is dissected and its function assessed with an electrical stimulator. After that, the surgeon opens the
carpal tunnel to visualize the median nerve. In the median nerve, the origin of the TBMN is identified near
the thenar eminence. This branch is divided proximally for 2/3 cm and coapted end-to-end towards the
ADQMB branch.

Ulnar nerve
As a result of injury to the ulnar nerve, grip and pinch weakness, and sometimes, clawing of the last two
ulnar digits occurs [15,16] . For proximal injuries, direct coaptation should reestablish sensation to the ulnar
digits [17-20] . However, after an immediate direct ulnar nerve repair, it is not possible to achieve recovery of
the innervation of the intrinsic musculature due to the long distance that the neurons must traverse for
[18]
nerve regeneration . Classical tendon transfers prevent deformities such as clawing, but they are often