The diagnosis of brachial plexus avulsion is often delayed by concomitant trauma to the arm and shoulder. Therefore, nerve transfer surgery to restore elbow and shoulder function is rarely reported. We present our initial experience of double fascicular nerve transfer for upper brachial plexus avulsion. A 26-year-old male patient presented with a 5-month history of unresolving pain and paralysis involving his left shoulder and elbow following a motorcycle accident. Avulsion of the C5 and C6 ventral roots and C6 dorsal root was confirmed by a myelographic computed tomography scan. After lesioning of the dorsal root entry zone due to painful avulsion, double fascicles (flexor carpi radialis and flexor carpi ulnaris) of the median and ulnar nerve) were transferred to the biceps brachii and brachialis branches of the musculocutaneous nerve to restore elbow flexion. Two weeks after the first transfer surgery, the distal accessory nerve was transferred to the suprascapular nerve to ensure shoulder function. Six months after the nerve transfers, elbow flexion recovered to Medical Research Council grade 3, but shoulder function did not show any improvement. An additional nerve transfer (triceps branch of the radial nerve to the axillary nerve) was planned for shoulder function. It is necessary to refine the microsurgical suture technique. For shoulder function, it is recommended to perform radial nerve transfer at the time of the first surgery.
Loss of shoulder and elbow function is typical of upper brachial plexus avulsion
Brachial plexus avulsion causes characteristic pain and paralysis in the upper extremities but often goes undiagnosed for years due to trauma to the shoulder and arm
A 26-year-old male patient presented with numbness and pain in the left arm and paralysis of the left shoulder and elbow after a motorcycle accident (
On physical examination, extension of the left shoulder as possible, but only up to 30 degrees of flexion (
Atrophy of the supraspinatus and infraspinatus and deltoid muscles of the left shoulder as well as atrophy of the left biceps brachii were observed (
After making an incision of about 20 cm in the upper arm of the left arm, the biceps and brachialis muscles were identified, the path of the musculocutaneous nerve, the branches to the biceps and brachialis muscles, and the lateral antebrachial cutaneous nerve were identified and neurolyzed (
A transverse incision 10 cm in length and 2 cm above the scapular spine was made. After elevation of the trapezius muscle, the distal accessory nerve was dissected and mobilized, and then divided distally (
No sensorimotor complication associated with nerve transfer surgery was detected. The first signs of reinnervation were seen 3 weeks after surgery. The patient showed minimal elbow flexion without resistance to gravity (MRC grade 2). However, shoulder abduction and extension did not improve. Elbow flexion improved 6 months to a full range of motion against gravity (MRC grade 3) (
In the case of brachial plexus avulsion, the absence of or inaccessible proximal nerve stump may not allow graft reconstruction. Therefore, motor nerve transfer is the only reconstructive option available
Nerve transfer is associated with multiple advantages. It allows dissection in uninjured and unscarred tissue planes and minimizes the regeneration time and distance. Optimal muscle reinnervation depends on sufficient number of regenerating motor axons reaching their target neuromuscular junctions within approximately 1 year following the injury
The choice of optimal donor nerve is based on factors such as the number of motor axons, location near the target muscle, and synergy of muscle function. Nerve branches that innervate muscle alone or motor fascicles that can be readily neurolyzed from a mixed nerve, such as the FCU fascicle of the ulnar nerve, are preferred donor nerves
Functional reconstruction following a complete brachial plexus injury is focused initially on restoration of elbow flexion, followed by shoulder abduction. Selection of the donor nerve with the largest caliber and the greatest number of motor axons is recommended
Oberlin et al.
Recognizing the superior functional outcome with reinnervation of the brachialis muscle, Mackinnon et al.
If the motor function of the median and ulnar nerves is not preserved in case of complete brachial plexus avulsion, medial pectoral and thoracodorsal nerves are suggested as alternative donor nerves for nerve transfer
In case of brachial plexus avulsion, shoulder abduction is the next priority, which entails reinnervation of the supraspinatus and infraspinatus muscles and deltoid
Splitting the scapular ligament at the scapular notch to secure the scapular nerve in the posterior approach was unfamiliar to us given our limited experience. However, the anatomical landmarks proposed by some authors
Due to the short follow-up period of 6 months, the authors fail to obtain good results with MRC grade 4 or higher in this case. Additional nerve transfer from the medial triceps branch of the radial nerve to the axillary nerve is currently planned for shoulder function with no visible improvement. We admit that despite performing theoretically rational nerve transfers based on suggestions of experienced authors
It was suggested that the decision regarding appropriate donor/recipient nerve configuration is based on the best tension-free orientation
Upper brachial plexus avulsion injuries involving C5 and C6 are the most common root avulsion injuries. Because it is a preganglionic injury, no feasible proximal nerve reconstruction procedure exists. Other options for the restoration of elbow and shoulder function include arthrodesis, which sacrifices motion and tendon transfer with suboptimal results. Recent developments in nerve transfer techniques yielded better results compared with traditional reconstructive procedures. Nerve transfers provide earlier reinnervation to the target muscles due to anatomic proximity compared with procedures performed at the root level.
No potential conflict of interest relevant to this article was reported.
Distribution of pain in brachial plexus avulsion and weakness and atrophy of the left shoulder and arm. (A) Schematic representation of the distribution of pain due to upper (C5-6) brachial plexus avulsion. Gray areas indicate the location of continuous severe paresthesia superimposed on stabbing pain during the onset of trauma (gray area). (B) Clinical photographs showing an absence of shoulder abduction (left and middle images). Severe atrophy was observed in the deltoid and infraspinatus muscles (arrows). There was no flexion of the right elbow (right). (C) Coronal and axial myelographic computed tomography images showing avulsion of the cervical roots. A coronal image (left) shows no travel of the left C5 and C6 ventral roots. At the level of C4, the left ventral root is not observed. At the C5 level, neither the left ventral nor the dorsal root is observed (middle and right images). (D) An intraoperative photograph showing the absence of the dorsal C6 rootlets due to avulsion. The dorsal rootlets of the C5 and C7 were preserved. Microsurgical dorsal root entry zone lesioning was performed (arrows) in the avulsed posterolateral sulcus.
Double fascicular nerve transfer for restoration of elbow function. (A) A schematic diagram showing the procedure of double fascicular nerve transfer. (B) An intraoperative photograph showing initial exposure of the branches of the musculocutaneous nerve (MCN) and median nerve (MN). (C) The redundant flexor carpi radialis fascicle (black arrow) was internally neurolyzed and cut. The mobilized, cut end of the biceps branch (white arrow) of the MCN enabled tension-free, end-to-end anastomosis. (D) Approximation of the cut edge of the brachialis branch (white arrow) of the MN and the flexor carpi ulnaris fascicle (black arrow) of the ulnar nerve (UN). (E) An intraoperative photograph showing double fascicular nerve transfer in the upper arm. Two anastomotic sites (white circles) are noted. LABC, lateral antebrachial cutaneous nerve of the musculocutaneous nerve; MABC, medial antebrachial cutaneous nerve.
Posterior approach to nerve transfer of the distal accessory to the suprascapular nerve for shoulder function. (A) An intraoperative photograph showing the exposure of the suprascapular notch via posterior approach. The spinal accessory nerve was identified with elevation of the trapezius muscle and intraoperative stimulation. The inset shows the incision location for the posterior approach. (B) Isolation of the suprascapular nerve after division of the suprascapular ligament at the suprascapular notch. (C) An intraoperative photograph showing end-to-end coaptation of the cut edges of the distal accessory and suprascapular nerves.
Clinical images showing the results of the nerve transfers at postoperative 6 months. The patient’s left elbow flexion improved to facilitate full range of motion (Medical Research Council grade 3). However, shoulder abduction improved only slightly.