Axillary to Radial Nerve Transfer for Elbow Extension in the Tetraplegic Patient: A Case Series

Recovery of upper extremity function is considered the top priority in the tetraplegic population. Midcervical injury often results in paralysis of the hand and loss of elbow extension. Elbow extension is essential for extending one's workspace and facilitating mobility (ie, self-transfer, wheelchair propulsion). Tendon transfers have traditionally been used to restore elbow extension, but the axillary to radial nerve transfer (ARNT) has emerged as a promising alternative. Our objective was to review a case series of single-surgeon outcomes for recovery of elbow extension in the tetraplegic population after ARNT.

An anterior, transaxillary approach for transfer of select branches of the axillary nerve to the long head triceps branch of the radial nerve was performed on adult traumatic spinal cord injury patients. Candidate screening consisted of physical examination and electrodiagnostic studies to determine absence of active elbow extension, presence of adequate axillary nerve function, Medical Research Council muscle power grade, American Spinal Injury Association Impairment Score motor level, and International Classification of Hand Surgery in Tetraplegia (ICHST) score. The participants and any identifiable individuals consented to publication of his/her image, and all patients consented to the procedure.

Fifteen adult patients (ages 18-59 years) with a C5 or C6 motor level underwent ARNT on 25 limbs with a minimum 15-month follow-up (3 lost to follow up). The median time from injury to surgery was 10 months. Primary outcome was Medical Research Council strength grade 3 (2-4) with illustrative videos of each outcome.

The ARNT provided at least M3 strength in 13 of 22 (59%) limbs. An additional 4 limbs achieved M2, providing functional benefit to the patient. Patients with a preoperative ICHST score of 3 or 4 all achieved antigravity strength overhead. No functional deficits due to donor nerve sacrifice was observed. Further investigation will be necessary to establish predictive factors for success of patients with ICHST scores 1 and 2. Overall, the ARNT is a good option for recovery of triceps function.