A 6-year-old girl is brought to the emergency department after falling from a chair onto her outstretched right arm. Physical examination shows swelling of the right elbow and tenderness to palpation over the distal humerus. Radial pulses are full and symmetric bilaterally. The patient is unable to cooperate with neurologic examination of the right hand due to significant pain. A peripheral intravenous line is placed, and analgesics are administered for pain control. X-rays show a supracondylar humeral fracture with anterolateral displacement of the proximal fracture fragment. Which of the following structures is most likely to be injured in this patient?

Question

A 6-year-old girl is brought to the emergency department after falling from a chair onto her outstretched right arm.  Physical examination shows swelling of the right elbow and tenderness to palpation over the distal humerus.  Radial pulses are full and symmetric bilaterally.  The patient is unable to cooperate with neurologic examination of the right hand due to significant pain.  A peripheral intravenous line is placed, and analgesics are administered for pain control.  X-rays show a supracondylar humeral fracture with anterolateral displacement of the proximal fracture fragment.  Which of the following structures is most likely to be injured in this patient?

Quizplus · Accepted Answer

11ec160b_35ee_6619_9249_13f79488a210_MD0001_00 Supracondylar humeral fractures are common pediatric elbow fractures that characteristically occur after hyperextension injuries (eg, falling onto an outstretched arm). These fractures carry a significant risk of neurovascular compromise, especially if the fragments are displaced. The brachial artery, median nerve, and radial nerve all run anterior to the elbow, with the brachial artery and median nerve over the medial epicondyle and the radial nerve over the lateral epicondyle. The median nerve and brachial artery are frequently injured in supracondylar fractures due to anteromedial displacement of the proximal fracture fragment (Choice C). However, this patient has intact radial pulses bilaterally (ie, sparing of the brachial artery) and anterolateral displacement of the proximal fracture fragment, making radial nerve injury more likely. Injury to the radial nerve at the elbow can result in wrist drop due to denervation of hand/finger extensor muscles, and sensory loss over the posterior forearm/dorsolateral hand. (Choice A) The basilic vein runs superficially over the medial aspect of the elbow and is not commonly injured during supracondylar fractures. (Choice B) The 2 heads of the biceps muscle originate from the scapula and insert onto the radius. Biceps tendon injury/rupture typically occurs in older patients following sudden extension of a flexed elbow while contracting the biceps (eg, lifting a heavy object). (Choice E) The ulnar nerve runs posterior to the medial epicondyle and can be injured with hyperflexion injuries (eg, falling onto a flexed elbow), resulting in posterior displacement of the proximal humerus or fracture of the medial epicondyle. Ulnar nerve injury at the elbow often presents with sensory loss over the fifth digit and half of the fourth digit, as well as weakness on flexion of the wrist and fourth/fifth digits. Educational objective: Supracondylar humeral fractures commonly occur after hyperextension of the elbow as a result of a fall onto an outstretched arm. The radial nerve runs along the anterolateral aspect of the elbow and is the structure most likely to be injured with anterolateral displacement of the proximal fracture fragment. The brachial artery runs with the median nerve on the anteromedial aspect of the elbow and will usually be spared in these patients (eg, intact radial pulse). __________ References: Nerve injuries associated with supracondylar fractures of the humerus in children (http://www.ncbi.nlm.nih.gov/pubmed/27235532)

A 6-Year-Old Girl Is Brought to the Emergency Department After