In a shoulder dislocation, which nerve injury must be ruled out?

In a shoulder dislocation, which nerve injury must be ruled out?

• A. Axillary nerve
• B. Median nerve
• C. Sciatic nerve
• D. Femoral nerve

Answer: (A)

The key idea is that the axillary nerve is the one most at risk with a shoulder dislocation. It travels right around the surgical neck of the humerus through the quadrangular space with the posterior circumflex humeral artery, so an anterior dislocation can stretch or compress it. This nerve supplies the deltoid and teres minor muscles and provides sensation over the lateral shoulder (the regimental badge area). If the axillary nerve is injured, you’ll see weakness of shoulder abduction beyond the initial 15 degrees (since the deltoid drives most of that movement) and numbness over the lateral shoulder. That’s why you must assess axillary nerve function after a shoulder dislocation. The other nerves listed (median, sciatic, femoral) are not typically affected by a shoulder joint injury, as they serve the forearm/hand or the legs, not the shoulder region.

The key idea is that the axillary nerve is the one most at risk with a shoulder dislocation. It travels right around the surgical neck of the humerus through the quadrangular space with the posterior circumflex humeral artery, so an anterior dislocation can stretch or compress it. This nerve supplies the deltoid and teres minor muscles and provides sensation over the lateral shoulder (the regimental badge area). If the axillary nerve is injured, you’ll see weakness of shoulder abduction beyond the initial 15 degrees (since the deltoid drives most of that movement) and numbness over the lateral shoulder. That’s why you must assess axillary nerve function after a shoulder dislocation. The other nerves listed (median, sciatic, femoral) are not typically affected by a shoulder joint injury, as they serve the forearm/hand or the legs, not the shoulder region.