Working Diagnosis:
Right ulnar nerve traction injury following displaced distal radius and ulna shaft metaphyseal junction fractures

Treatment:
Decision was made not to perform nerve exploration surgery given location and mild angulation of fractures. 10 weeks after injury, patient had continued numbness of the 5th digit and inability to abduct or adduct the 4th and 5th fingers. However, his numbness to the hypothenar skin had progressively improved with conservative management. His parents continued to elect conservative treatment.

Outcome:
Patient spent 6 weeks of his recovery with immobilization for fracture healing and an additional 8 weeks with allowed motion. He had continual improvement in sensation and grip strength, and was able to return to sport. Patient continued to move 4th and 5th digits through passive ROM and followed monthly for tracking improvements of ulnar nerve palsy. He achieved complete sensation and motor function of his ulnar nerve by 4 months.

Author's Comments:
Ulnar nerve paralysis is an unusual complication of radial and ulnar fractures with few published cases. Ulnar nerve laceration, entrapment, contusion, or traction injury must be considered. Treatment can range from conservative nonoperative management with observation for continuing neural improvement, to surgical nerve exploration with possible nerve repair. Ulnar nerve traction injuries can be treated conservatively, whereas nerve lacerations and entrapment should undergo surgical exploration. Important aspects to consider are locations (mid vs distal shaft) and displacement of fractures. Close follow up of patients is imperative as distinguishing between nerve injuries is critical.

Editor's Comments:
Nerve injuries are a rare but significant complication of long bone fractures, and care should be taken to fully evaluate neurologic function at the time of injury and at each subsequent office visit. Iatrogenic causes of nerve deficits, including compartment syndrome and injuries secondary to reduction, should be considered on evaluation. Injuries vary in type and severity, and the more significant may require operative treatment. In non-operative cases, patients should be monitored closely for improvement throughout their recovery.

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