A 28-year-old man sustains a fracture of the medial epicondyle of the humerus. Which of the following functional deficits would be expected?

• A Wrist drop with loss of finger extension
• B Inability to oppose the thumb with weakness of thenar muscles
• C Loss of sensation over the lateral three-and-a-half digits
• D Loss of ring and little finger flexion and interosseous muscle function with claw hand worsened by trying to flex the fingers ✓

Explanation

Medial epicondyle fracture injures the ulnar nerve (which passes in the groove behind the medial epicondyle). Ulnar nerve injury causes weakness of the medial two lumbricals, all interossei, hypothenar muscles, and the medial half of flexor digitorum profundus. This produces a claw hand most pronounced in the ring and little fingers (ulnar paradox: low ulnar lesions cause more pronounced claw because flexor digitorum profundus to fingers 4–5 is also preserved in high lesions, reducing the claw deformity). Wrist drop indicates radial nerve injury; thenar weakness indicates median nerve injury.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.