A patient with a deep laceration at the medial epicondyle level presents with clawing of ring and little fingers, weakness of finger abduction and adduction, and loss of sensation on the medial 1.5 fingers. Flexion of the DIP joint of the little finger is also lost. What is the level of ulnar nerve injury?

• A At the wrist (Guyon's canal)
• B At the midforearm
• C At the axilla
• D At the elbow (medial epicondyle level) ✓

Explanation

Injury at the medial epicondyle affects the ulnar nerve before it enters the forearm, damaging flexor carpi ulnaris and the medial half of flexor digitorum profundus (FDP to ring and little finger) — hence DIP flexion of the little finger is lost. Clawing is less severe at the elbow level (paradoxically, because FDP loss reduces the 'resting flexion' at DIP). At wrist (Guyon's canal), FDP function is preserved, DIP flexion intact, and the claw deformity of ring/little fingers is MORE pronounced ('ulnar paradox'). The sensory distribution is identical at both levels.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.