A woman presents with weakness of adduction of all fingers and wasting of the interossei following a fracture of the hook of hamate. Which nerve territory is compromised?

• A Deep branch of the ulnar nerve ✓
• B Median nerve – recurrent branch
• C Superficial branch of the radial nerve
• D Anterior interosseous nerve

Explanation

The deep branch of the ulnar nerve passes through Guyon's canal and curves around the hook of hamate to supply all the interossei, medial two lumbricals, adductor pollicis, and hypothenar muscles (except palmaris brevis). A fracture of the hook of hamate can compress this deep motor branch, producing intrinsic muscle wasting and loss of finger adduction and abduction without sensory loss.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.