Modified Partial Radial to Axillary Nerve Transfer as the Index Procedure for Isolated Axillary Nerve Injury

Area of Science:

• Orthopedic Surgery
• Neurosurgery
• Microsurgery

Background:

• Axillary nerve injuries lead to significant functional impairment.
• Current treatments are often limited to salvage procedures after conservative management fails.
• Nerve transfer offers a potential alternative for restoring shoulder function.

Purpose of the Study:

• To evaluate the efficacy of partial radial-to-axillary nerve transfer as an index procedure for axillary nerve injury.
• To assess functional outcomes and donor-site morbidity.
• To investigate the impact of timing on surgical outcomes.

Main Methods:

• Retrospective analysis of a single-surgeon cohort with isolated axillary nerve injury.
• Minimum 2-year follow-up data including shoulder range of motion and Medical Research Council (MRC) strength scores.
• Electromyography (EMG) for diagnosis and intra-operative deltoid muscle biopsies for motor endplate (MEP) analysis in 8 patients.

Main Results:

• Significant improvements in MRC scores (average increase of 2.82) and shoulder range of motion (forward flexion, abduction, external rotation) (p<0.01).
• Motor endplates (MEPs) were observed in denervated muscles even in patients operated on >6 months post-injury.
• No detectable donor-site morbidity was reported.

Conclusions:

• Partial radial-to-axillary nerve transfer is a viable index procedure for isolated axillary nerve injury.
• The procedure can significantly restore shoulder motion and functional strength.
• Functional improvement is possible even with delayed treatment, correlating with persistent deltoid MEPs.