During axillary lymph node clearance, the surgeon identifies a nerve running on the anterior surface of latissimus dorsi. Division of this nerve will produce weakness of which movements?

• A Abduction beyond 90 degrees and lateral rotation of the shoulder
• B Adduction, extension and medial rotation of the shoulder ✓
• C Elevation and retraction of the scapula
• D Flexion and adduction of the shoulder

Explanation

The thoracodorsal nerve (C6, C7, C8), from the posterior cord, descends on the anterior surface of latissimus dorsi and is at risk during axillary dissection. Latissimus dorsi adducts, extends and medially rotates the humerus, as in climbing or swimming strokes. Abduction above the horizontal is performed by the deltoid supplied by the axillary nerve, and scapular retraction is rhomboid function via the dorsal scapular nerve, killing both other options.

Reference: Snell's Clinical Anatomy by Regions, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.