A 68-year-old woman comes to the emergency department due to pain in the left upper arm after a fall from standing height. Medical history is significant for hypothyroidism and hypertension. Physical examination shows bruising of the shoulder. Left arm movement is limited due to pain. Plain radiographs reveal a nondisplaced left humerus fracture at the anatomical neck. This patient is at greatest risk for which of the following complications?

Question

A 68-year-old woman comes to the emergency department due to pain in the left upper arm after a fall from standing height.  Medical history is significant for hypothyroidism and hypertension.  Physical examination shows bruising of the shoulder.  Left arm movement is limited due to pain.  Plain radiographs reveal a nondisplaced left humerus fracture at the anatomical neck.  This patient is at greatest risk for which of the following complications?

Quizplus · Accepted Answer

11ec160b_35f9_1489_9249_8dd6ae224f56_MD0001_00 This patient suffered a fracture of the proximal humerus at the anatomical neck. Humeral neck fractures commonly occur in falls; risk factors include age >65 and osteoporosis. They often occur as isolated injuries but may also be associated with glenohumeral dislocation. The proximal humerus and glenohumeral joint receive their blood supply via the anterior and posterior circumflex humeral arteries, which are branches of the axillary artery that form an anastomosis encircling the neck of the humerus in the quadrangular space. This anastomosis gives rise to intraosseous arteries that travel back to the humeral head; humeral neck fractures can disrupt this retrograde blood flow, leading to avascular necrosis (osteonecrosis) of the humeral head. Osteonecrosis presents insidiously with shoulder pain, decreased range of motion, and flattening of the humeral head on x-ray. (Choice A) Biceps tendon rupture presents with weakness of shoulder flexion and a noticeable bulge in the anterior arm. It most commonly occurs due to chronic overuse tendinopathy or acute forceful contraction of the biceps, but humeral neck fracture does not usually disrupt the tendon. (Choices B and D) Supracondylar fracture may injure the brachial artery and median nerve where they pass anterior to the distal humerus. These structures are not at risk from proximal humerus fracture. (Choice E) The radial nerve and deep brachial artery run posterior to the midshaft of the humerus and may be injured by a fracture at that point. These structures are not typically injured in a humeral neck fracture. Educational objective: The proximal humerus and glenohumeral joint receive their blood supply via the anterior and posterior circumflex humeral arteries, which are branches of the axillary artery that form an anastomosis at the neck of the humerus. Humeral neck fractures can disrupt this blood flow, leading to avascular necrosis of the humeral head.

A 68-Year-Old Woman Comes to the Emergency Department Due to Pain