Ulnar Nerve Injury in Pediatric Midshaft Forearm Fractures: A Case Series.

ABSTRACT

OBJECTIVES: To describe a midshaft forearm fracture pattern that places the ulnar nerve at risk in the pediatric population and provide 7 clinical case examples describing the injury pattern and treatment methods. DESIGN: Retrospective observational case series, review of literature, cadaver dissection, and treatment recommendations. SETTING: Multi-institutional, Southeast United States. PATIENTS Seven pediatric patients (5 male and 2 female) with mean age of 8.7 years (range, 3-14) who sustained a significantly displaced closed, or grade I open, middle to distal one-third both-bone forearm fracture with subsequent ulnar nerve dysfunction. INTERVENTIONS: Manual reduction and casting of both-bone forearm shaft fractures, operative debridement, fracture fixation, nerve exploration, neurolysis, nerve repair, and nerve grafting. MAIN OUTCOME MEASUREMENTS Radiographic fracture union, clinical ulnar nerve motor and sensory function testing, along with selective electric nerve testing and advanced imaging were monitored throughout follow-up postinjury. RESULTS: Five of 7 patients underwent surgical treatment and 2 others were treated with conservative measures. The ulnar nerve was entrapped within the fracture site of one patient with an open fracture along with partial nerve transection, and 4 patients were found to have the nerve encased in hypertrophic scar tissue or bony callus upon surgical exploration at 3-12 months postinjury. CONCLUSIONS: The ulnar nerve lies in a precarious position in the middle to distal one-third forearm and is bound by anatomic constraints that place the nerve at risk of injury. This article offers a treatment algorithm that includes conservative treatment, acute exploration, early exploration (≤3 months), and late exploration (>3 months). LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.