What nerve is at risk during a Holstein-Lewis fracture?

A Holstein-Lewis fracture is a specific type of humeral shaft fracture that occurs in the middle or distal third of the humerus. This fracture is particularly notable for its association with injury to the radial nerve, which runs closely alongside the humerus. When a Holstein-Lewis fracture occurs, the radial nerve can become damaged due to the displacement of bone fragments or direct trauma at the site of the fracture.

Understanding the anatomy of the arm is critical; the radial nerve controls muscles that extend the wrist and fingers and provides sensation to parts of the hand. Injury to this nerve may lead to wrist drop, where the individual cannot extend their wrist or fingers. Therefore, awareness of the radial nerve's location and its function is crucial in assessment and management following such a fracture.

While the other nerves mentioned—ulnar, median, and musculocutaneous—are important in upper limb function and may be injured in different contexts (such as other types of fractures or lesions), they are not specifically at risk with a Holstein-Lewis fracture. This is why the radial nerve stands out as the nerve predominantly at risk in this scenario.