A 19-year-old man is brought to the emergency department after he punched through a plate glass window with his right arm. Initially there was profuse bleeding, but it stopped after direct pressure was maintained by emergency medical personnel. A deep laceration is present at the proximal aspect of the right cubital fossa, just lateral to the medial epicondyle. Examination reveals absent sensation in the lateral palm and the palmar surfaces of the first 3½ fingers, inability to flex the proximal interphalangeal joints, and inability to pronate the forearm. Additional injury to which of the following structures was most likely responsible for this patient's bleeding?

Question

A 19-year-old man is brought to the emergency department after he punched through a plate glass window with his right arm.  Initially there was profuse bleeding, but it stopped after direct pressure was maintained by emergency medical personnel.  A deep laceration is present at the proximal aspect of the right cubital fossa, just lateral to the medial epicondyle.  Examination reveals absent sensation in the lateral palm and the palmar surfaces of the first 3½ fingers, inability to flex the proximal interphalangeal joints, and inability to pronate the forearm.  Additional injury to which of the following structures was most likely responsible for this patient's bleeding?

Quizplus · Accepted Answer

11ec160b_35e9_d22f_9249_4351ff40c9d1_MD0001_00 This patient's cubital fossa laceration has resulted in median nerve injury, leading to impairment of forearm pronation (pronator teres) and proximal interphalangeal joint flexion (flexor digitorum superficialis), along with sensory deficits in the median distribution. Because the brachial artery is adjacent to the median nerve at the cubital fossa, injury to the brachial artery was most likely responsible for this patient's bleeding. The brachial artery is the continuation of the axillary artery as it extends past the inferior border of the teres major muscle. In the upper arm, the brachial artery courses in the medial bicipital groove between the biceps brachii and triceps brachii muscles, giving off multiple branches (eg, deep brachial artery) and running alongside both the median and ulnar nerves. Proximal to the elbow, the median and ulnar nerves diverge; only the median nerve accompanies the brachial artery through the cubital fossa (lateral to the medial epicondyle) into the proximal anterior forearm, where the brachial artery splits into the radial and ulnar arteries. In contrast, the ulnar nerve travels posterior to the medial epicondyle. (Choice A) The anterior interosseous artery runs alongside the anterior interosseous nerve, a branch of the median nerve that supplies most of the deep volar forearm muscles. The anterior interosseous nerve and artery originate in the forearm, distal to the cubital fossa. (Choice C) The deep brachial artery is the first branch off the brachial artery in the upper arm. It courses posterior to the humerus and is vulnerable to injury with humeral shaft fractures. (Choices D and E) Shortly after originating from the brachial artery in the forearm, the radial artery gives off the radial recurrent artery, which ascends in proximity to the radial nerve near the lateral epicondyle. The radial artery then accompanies the superficial branch of the radial nerve through most of the forearm. The absence of radial nerve deficits and laceration location (cubital fossa near medial epicondyle) make injury to these vessels unlikely. (Choice F) The ulnar artery originates from the brachial artery in the forearm (distal to the medial epicondyle). It runs alongside the ulnar nerve through most of the forearm. Educational objective: The brachial artery runs alongside the median and ulnar nerves in the medial bicipital groove of the upper arm. Proximal to the elbow, the median and ulnar nerves diverge, and the brachial artery continues with the median nerve through the cubital fossa. Injury to the median nerve at the cubital fossa frequently injures the brachial artery. __________ References: Relationship of the median and radial nerves at the elbow: application to avoid injury during venipuncture or other invasive procedures of the cubital fossa. (http://www.ncbi.nlm.nih.gov/pubmed/28413740)

A 19-Year-Old Man Is Brought to the Emergency Department After