Surgical Algorithm and Results of Isolated Traumatic Axillary Nerve Injuries

Axillary nerve injuries are common and typically occur during high-energy, traumatic events. The purpose of this study is to propose a treatment algorithm for acute isolated axillary nerve injuries and report the outcomes of surgically treated patients.

A retrospective review identified 14 patients surgically treated for an isolated axillary nerve injury. Axillary nerve neurolysis was performed for all patients, and a triceps branch of the radial nerve was transferred to the axillary nerve in patients without evidence of deltoid function following intraoperative axillary nerve stimulation. Four patients were treated with neurolysis alone and 10 patients received a transfer. Pre- and postoperative deltoid strength, shoulder abduction, and the Disabilities of the Arm, Shoulder, and Hand (DASH) outcome score were evaluated.

At most recent follow-up, both the neurolysis and nerve transfer groups had significant improvement in deltoid strength, with 86% achieving M4 or greater. Shoulder abduction improved from a mean of 63 to 127 degrees. This difference was significant in the nerve transfer group and when all patients were analyzed together. DASH scores significantly improved from a mean of 47 to 34 when all patients were analyzed together. No patients experienced a decrease in elbow extension strength following nerve transfer.

In patients with preserved triceps strength, a triceps branch of the radial nerve can be coapted directly to the axillary nerve in the absence of deltoid contraction following electrical stimulation. Functional improvements were seen in patients treated with neurolysis alone and in combination with nerve transfer, supporting the use of intraoperative axillary nerve stimulation to guide treatment.