American Board of Surgery Qualifying Exam (ABS QE) Practice Test

In a distal radius fracture, which nerve is often compromised?

1. Radial nerve

2. Median nerve

3. Ulnar nerve

4. Axillary nerve

The correct answer is: Median nerve

In the context of a distal radius fracture, the median nerve is frequently compromised due to its anatomical path and proximity to the fracture site. The median nerve runs through the forearm and crosses the wrist under the flexor retinaculum to enter the hand, making it susceptible to injury when a fracture occurs in the distal radius. A specific type of distal radius fracture, known as a Colles' fracture, often leads to dorsal angulation and potential displacement that can impact the median nerve. This can result in variable symptoms, including numbness and weakness in the distribution of the median nerve, which innervates parts of the hand and fingers, particularly affecting the ability to flex the thumb and index finger. In contrast, although the radial nerve is also close to the distal radius, its typical injuries are associated more with mid-shaft humeral fractures than with wrist injuries. The ulnar nerve, while crucial for hand function, is located more medially and is less likely to be affected by a standard distal radius fracture. The axillary nerve is primarily involved with shoulder function and does not have a direct role in distal radius injuries. Thus, the median nerve's anatomical pathway makes it the most frequently affected nerve in the context of distal radius fractures