American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Which nerve is commonly affected in an anterior shoulder dislocation?

1. Radial nerve

2. Median nerve

3. Ulnar nerve

4. Axillary nerve

The correct answer is: Axillary nerve

In the context of an anterior shoulder dislocation, the axillary nerve is particularly vulnerable due to its anatomical proximity to the shoulder joint. The axillary nerve innervates the deltoid and teres minor muscles and provides sensation to the skin overlying the lateral aspect of the shoulder. When the shoulder dislocates anteriorly, the nerve may become stretched or compressed, leading to specific clinical manifestations such as weakness in arm abduction (especially at the shoulder) and loss of sensation in the area supplied by the nerve. The other nerves listed in the choices—radial, median, and ulnar—have different anatomical courses and functions. The radial nerve primarily innervates the posterior aspects of the arm and forearm and is less likely to be injured in shoulder dislocations. The median nerve mostly runs along the anteromedial aspect of the forearm and hand, while the ulnar nerve is located more medially, primarily affecting the hand and not typically involved in shoulder joint pathology. Therefore, the axillary nerve's role and its path make it the most commonly affected nerve in the event of an anterior shoulder dislocation.