Traumatic Rupture of the Coracobrachialis Muscle: A Case Report

Rupture of the coracobrachialis muscle is extremely rare; to the best of our knowledge, rupture of this muscle from indirect, nonpenetrating trauma has yet to be reported1,2. This case report describes a distal coracobrachialis rupture that was caused by indirect trauma. Because of the progression of the injury and its clinical presentation, along with the rarity of a coracobrachialis rupture, the patient was initially diagnosed with a distal biceps tendon rupture at an outside institution, which delayed treatment. The coracobrachialis muscle functions as a flexor of the shoulder. Additionally, it serves as an adductor and internal rotator of the shoulder and stabilizes the shoulder joint when the arm is at the side. It inserts via a flat tendon in the middle third of the humerus, between the origins of the brachialis and triceps muscles3. It is important to be aware of the rare rupture of the coracobrachialis muscle because it may be misdiagnosed as a distal biceps tendon rupture. We aim to emphasize the importance of recognizing this unusual injury and to present a surgical treatment option. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A forty-one-year-old oil rig worker was lifting a heavy piece of equipment by elevating his arm and flexing his elbow when the machine suddenly jerked. He felt a tearing sensation and had substantial pain and deformity in the right arm. Initially, he was seen by an emergency physician, who diagnosed a distal biceps tendon rupture because of the bulging deformity at the medial aspect of the upper arm, as well as weakness and pain during elbow flexion. He did poorly with nonoperative treatment and was referred to an orthopaedic surgeon for consultation. Magnetic resonance imaging (MRI) of the right …