Transfer of the radial branch of the superficial radial nerve to the sensory branch of the ulnar nerve for sensory restoration after C7-T1 brachial plexus injury

Combined Nerve and Tendon Transfers for C7-T1 Brachial Plexus Avulsion Injury

BACKGROUND

In patients with C7-T1 brachial plexus avulsions, complete loss of hand function is commonly seen. However, the reconstruction of hand function is difficult.

OBJECTIVE

To report the outcomes of hand function recovery after combined nerve and tendon transfers in C7-T1 brachial plexus injury.

METHODS

From 2012 to 2019, 8 patients with C7-T1 brachial plexus injury underwent combined nerve and tendon transfers for hand function restoration, which included the following: (1) the pronator teres motor branch to the anterior interosseous nerve and brachialis motor branch to the flexor digitorum superficialis branch for finger flexion, (2) the supinator motor branch to the posterior interosseous nerve for finger extension, (3) the brachioradialis tendon transfer for thumb opposition, and (4) the radial branch of the superficial radial nerve to the sensory branch of the ulnar nerve for sensory reconstruction. Patients were evaluated for functional improvement of finger flexion, finger extension, thumb opposition, and sensory recovery.

RESULTS

No clinical donor deficits were observed. Seven of eight patients recovered finger and thumb flexion (4 patients scored British Medical Research Council grade M4 and 3 scored M3). The average grip strength was 3.4 kg. All patients regained finger extension (4 scored M4 and 4 scored M3), thumb opposition, and protective sensation on the ulnar hand. Patients were able to use their reconstructed hands in daily lives.

CONCLUSION

Combined nerve and tendon transfers are reliable and effective. This strategy could be an option for hand function reconstruction after C7-T1 brachial plexus injury.

Sensory Neurotization of the Ulnar Nerve, Surgical Techniques and Functional Outcomes: A Review

When ulnar nerve lesions happen above the wrist level, sensation recovery after acute repair or nerve grafting is often challenging. Distal sensory nerve transfers may be an option for overcoming these sequelae. However, little data has been published on this topic. This study aims to review the surgical procedures currently proposed, along with their functional results. Six donor nerves have been described at the wrist level: the palmar branch of the median nerve, the cutaneous branch of the median nerve to the palm with or without fascicles of the ulnar digital nerve of the index finger, the posterior interosseous nerve, the third palmar digital nerve, the radial branch of the superficial radial nerve, the median nerve, and the fascicule for the third web space. Three donor nerves have been reported at the hand level: the ulnar digital nerves of the index, and the radial or ulnar digital nerves of the long finger. Three target sites were used: the superficial branch of the ulnar nerve, the dorsal branch of the ulnar nerve, and the ulnar digital branch of the fifth digit. All the technical points have been illustrated with anatomical dissection pictures. After assessing sensory recovery using the British Medical Research Council scale, a majority of excellent recoveries scaled S3+ or S4 have been reported in the targeted territory for each technique.

Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer

Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.

Sensory Nerve Transfer for Lower Roots Brachial Plexus Injury: Superficial Radial Nerve to the Dorsal Cutaneous Branch and the Superficial Branch of the Ulnar Nerve

In the treatment of brachial plexus injury to lower nerve roots, the priority is to restore motor function to the paralyzed hand. In addition, it is also important to consider sensory reconstruction, which is crucial to the optimal restoration of prehensile function. We report the surgical technique and sensory recovery of a nerve transfer in a case in which the superficial radial nerve was transferred to the dorsal cutaneous branch and the superficial branch of the ulnar nerve in a patient with C7, C8, and T1 roots injury. The nerve transfer successfully restored sensation in the ulnar one and a half digits as well as the ulnar border of the hand, with minimal donor site deficit. This technique provides a useful sensory reconstructive option in patients with brachial plexus injury to lower roots.

Novel Uses of Nerve Transfers

Nerve transfer surgery involves using a working, functional nerve with an expendable or duplicated function as a donor to supply axons and restore function to an injured recipient nerve. Nerve transfers were originally popularized for the restoration of motor function in patients with peripheral nerve injuries. However, more recently, novel uses of nerve transfers have been described, including nerve transfers for sensory reinnervation, nerve transfers for spinal cord injury and stroke patients, supercharge end-to-side nerve transfers, and targeted muscle reinnervation for the prevention and treatment of postamputation neuroma pain. The uses for nerve transfers and the patient populations that can benefit from nerve transfer surgery continue to expand. Awareness about these novel uses of nerve transfers among the medical community is important in order to facilitate evaluation and treatment of these patients by peripheral nerve specialists. A lack of knowledge of these techniques continues to be a major barrier to more widespread implementation.