Staged Brachialis to Anterior Interosseous Nerve Transfer With Graft for Recovery of Grasp in the Tetraplegic Patient: Technical Report.

BACKGROUND AND

OBJECTIVES

Nerve transfers have been shown to restore upper-extremity function after cervical spinal cord injury, but recovery of hand grasp remains a challenge. The brachialis (BRA) to anterior interosseous nerve (AIN) nerve transfer is the most common nerve transfer used to recover finger flexion. The BRA-AIN transfer has been reported to have less favorable outcomes compared with other nerve transfers, which is attributed to long regenerative distances and axonal dispersion from proximal interconnecting fascicles. We propose a simpler variation of this procedure to both avoid the proximal interfascicular connections and to limit the denervation time of the recipient with a staged procedure using an interposed nerve graft.

METHODS

Preoperative assessment includes physical examination and electrodiagnostic studies to confirm preserved innervation of both the BRA donor and the backup elbow flexor, biceps brachii. In Stage 1, the BRA branches are coapted to the reversed medial antebrachial cutaneous nerve autograft and the distal graft is tunneled into the forearm and left in the subcutaneous tissue. In Stage 2, 4-6 months later, the distal graft is identified in the forearm and coapted to the AIN branch.

RESULTS

The medial brachial exposure allows for access to both the medial antebrachial cutaneous nerve graft and the BRA nerve. The graft is marked with a Prolene suture for easy identification in the second-stage procedure when tension-free coaptation to the AIN is performed to achieve finger flexion. Preliminary outcomes in 23 limbs at a minimum of 1 year after the procedure demonstrated 78% achieving at least an Medical Research Council 3 best finger flexion.

CONCLUSION

The BRA-AIN is one of the few interventions available for recovery of hand grasp in the tetraplegic patient, but previous reports have shown less favorable outcomes. A 2-stage approach with an interpositional graft may address some of the limitations of the direct BRA-AIN transfer, improving outcomes.