Ulnar nerve palsy associated with fracture of the distal radius

To describe the clinical features and outcome of a series of patients with complete motor and sensory ulnar nerve palsy associated with a fracture of the distal radius.

Retrospective case series.

Level 1 trauma center.

Five adults with acute complete motor and sensory ulnar nerve palsy associated with fracture of the distal radius were treated during a 2 year period. There were 3 men and 2 women, with an average age of 42 years (range, 33 to 56 years). All 5 distal radius fractures were high energy and widely displaced. Three patients had an associated ulna fracture (2 styloid, 1 styloid and distal diaphysis), and 1 had a complete triangular fibrocartilage complex (TFCC) avulsion from the distal ulna (associated with an open wound). Two patients had open fractures.

Open reduction and internal fixation of the distal radius fracture in 4 patients and external fixation in 1 patient. Three patients had exploration and release of the ulnar nerve because it was associated with an acute carpal tunnel syndrome.

Recovery of ulnar nerve function.

At an average follow-up of 17 months, 4 patients had complete or near-complete recovery of ulnar nerve function. One patient had moderate motor and mild sensory dysfunction.

Acute ulnar nerve palsy may occur in association with high-energy, widely displaced fractures of the distal radius. These are usually neurapraxic injuries that recover to normal or near-normal strength and sensation. We recommend exploration and release of a complete ulnar nerve palsy associated with a fracture of the distal radius fracture when there is an open wound or an acute carpal tunnel syndrome, and observation without exploration otherwise.