Review Question - QID 109205

This patient is presenting after significant trauma with an inability to extend the wrist suggesting a diagnosis of a midshaft humeral fracture.

A midshaft humeral fracture typically occurs after significant trauma and can result in damage to the radial nerve. The radial nerve innervates the posterior compartment of the arm and forearm. Damage or impingement of this nerve can present with weakness of extension of the forearm, wrist, and fingers depending on the location of the injury. It can also present with a loss of sensation over the dorsum of the distal forearm and lateral hand.

Illustration A is a radiograph that demonstrates a midshaft humeral fracture.

Incorrect Answers:
Answer 1: A humeral neck fracture could cause damage to the axillary nerve. Patients will present with weakness upon abducting the arm with this injury.

Answer 3: A supracondylar fracture could damage the median nerve (if the damage is medial) or the ulnar nerve (if the damage is lateral). Patients could present with deficits of the median nerve (loss of sensation/motor function of the lateral three digits) or ulnar nerve (loss of sensation/motor function of the medial two digits).

Answer 4: An ulnar fracture could represent a Monteggia fracture which presents with a fracture of the ulna and dislocation of the radius. There will typically be a decreased range of motion of the forearm at the elbow.

Answer 5: A radial fracture could represent a Galeazzi fracture which presents with fracture of the radius and subluxation of the distal radio-ulnar joint. On presentation there would be limited pronation/supination and potentially an anterior interosseous nerve palsy.

Bullet Summary:
A midshaft humeral fracture could damage the radial nerve and cause weakness of extension of the forearm and wrist.