Injury to ulnar nerve

This code signifies damage or trauma to the ulnar nerve, a major nerve in the arm that provides sensation to the little finger and half of the ring finger, and controls several muscles in the hand and forearm. This injury can result in sensory deficits, motor weakness, or paralysis in the affected distribution.

Apply this code when documentation clearly indicates a specific injury to the ulnar nerve, such as from a fracture, laceration, compression (e.g., cubital tunnel syndrome), or direct trauma. Supporting documentation should detail the mechanism of injury and the specific nerve affected.

• Differentiate from other peripheral nerve injuries of the upper extremity; ensure the documentation explicitly states "ulnar nerve."
• Code any associated open wounds, fractures, or dislocations separately.
• Consider an additional E code to describe the external cause of the injury.