Ultrasound of the ulnar nerve after elbow fracture

Axial ultrasound images of the ulnar nerve adjacent to the medial epicondyle.
(A) Ultrasound from a patient with longstanding symptoms of ulnar neuropathy after an elbow fracture. The region of interest used to calculate the cross-sectional area of the ulnar nerve is indicated with a dashed circle. The cross-sectional area of this nerve is 31 mm², three times the normal size of the nerve as shown in image B. The diagnosis was confirmed with electrodiagnostic studies showing ulnar motor conduction block, loss of sensory nerve action potentials, and significant motor nerve conduction velocity slowing across this site.
(B) Ultrasound from an asymptomatic, age-matched control.