A 25-year-old with a stab wound to the axilla presents with inability to abduct the shoulder beyond 30°, loss of sensation over the lateral aspect of the upper arm, and weakness of deltoid. The nerve injured is:
- A Suprascapular nerve
- B Long thoracic nerve
- C Axillary nerve ✓
- D Musculocutaneous nerve
Correct answer: C. Axillary nerve
Explanation
The axillary nerve arises from the posterior cord of the brachial plexus (C5–C6) and winds around the surgical neck of the humerus, supplying the deltoid and teres minor muscles and the regimental badge area of sensation (lateral upper arm). Injury causes deltoid paralysis with inability to abduct the arm beyond the first 15–30° (supraspinatus initiates abduction) and sensory loss over the lateral upper arm. It is also commonly injured in anterior shoulder dislocations.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.