Outcomes in restoration of shoulder abduction in upper trunk brachial plexus injuries: a randomized study comparing ipsilateral C7 fascicle and spinal accessory nerve as donor nerves

Background

Spinal accessory nerve (SAN) transfer is commonly used to reanimate the suprascapular nerve (SSN) in traumatic brachial plexus injuries (BPI). Despite its technical simplicity and satisfactory results, this transfer has two disadvantages: the inadequacy of the number of nerve fibers between donor and recipient and the weakening of the trapezius muscle. To avoid this, we transferred a fascicle from the C7 root for the pectoralis major muscle to the suprascapular nerve for shoulder abduction.

Methods

Patients with traumatic upper trunk brachial plexus injury presenting within 6 months of injury were randomly allocated to study & control groups. The control group underwent SAN to SSN transfer, and the study group underwent C7 fascicle to SSN transfer. Transfer of the radial nerve branch to the triceps’ long head to the axillary nerve’s anterior branch and fascicle transfer to the musculocutaneous branches to the biceps and brachialis was also considered.

Results

A total of 13 patients were included in the study from August 2022 to December 2024. The control group comprised 7 patients with a mean age of 22.7 years (14–32 years), and the study group comprised 6 patients with a mean age of 34.8 years (16–38 years). At a mean follow up of 18.3 months (range of 12–28 months) in the study group, two of the 6 patients had shoulder abduction recovery power of M3 whereas 4 patients had MRC ≥ 3 recovery in shoulder abduction among the control group (M4-2, M3-2) at 20.6 months (range of 14–35 months) of follow up. However, there was no statistically significant difference observed in the shoulder recovery outcomes (p = 0.706).

Conclusion

There was no significance in the functional recovery of shoulder abduction power & active range of motion among the two groups.