A 40-year-old man is injured in a car accident and fractures his left elbow. He now complains of numbness of his fourth and fifth fingers, and weakness in his hand grip. Neurologic findings confirm weakness of handgrip with weakness of finger abduction and adduction, and decreased sensation over the fifth finger and lateral aspect of fourth finger. Which of the following is the most likely diagnosis?
High-Yield Explanation
Injury to the ulnar nerve results in impaired adduction and abduction of the fingers. The nerve is commonly injured in elbow dislocations and fractures. The fibers arise from the eighth cervical and the first thoracic segments. The ulnar is a mixed nerve with sensory supply to the medial hand.