Procedure 14 Distal Anterior Interosseous Nerve Transfer to Motor Branch of Ulnar Nerve
See Video 12: Distal Anterior Interosseous Nerve Transfer to Motor Branch of Ulnar Nerve
Indications
For recovery of intrinsic muscle function in a patient with a high ulnar nerve injury (near or above the elbow) to shorten the distance between the donor nerve and the recipient muscles
Examination/Imaging
Clinical Examination
Check motor function of the anterior interosseous nerve (AIN).
Surgical Anatomy
The ulnar nerve enters the anterior (flexor) compartment of the forearm between the two heads of flexor carpi ulnaris (FCU) and innervates one and a half muscles (FCU and medial half of FDP to the ring and small fingers). It runs along the ulna with the ulnar artery, and the two travel distally under the FCU. Proximal to the wrist, the fascicles of the motor branch lie ulnar to the sensory fascicles. The ulnar nerve and artery pass superficial to the flexor retinaculum into the Guyon canal. In the Guyon canal, the ulnar artery is radial to the ulnar nerve. At the radial side of the pisiform bone, the ulnar nerve is divided into the superficial and deep branches. The deep branch of the ulnar nerve curves laterally to supply the hypothenar muscles and runs across the palm with the deep palmar arch; it terminates by supplying the first dorsal interosseous and the deep head of the flexor pollicis brevis (Fig. 14-1).
The AIN is a branch of the median nerve that supplies the deep muscles on the front of the forearm. It accompanies the anterior interosseous artery and runs on the anterior surface of the interosseous membrane in the interval between the FPL and FDP, supplying the whole of the former and the radial half of the latter. The AIN terminates in the volar capsule of the wrist joint after it innervates the PQ (see Fig. 14-1).
