This 16-year-old male has a right arm contusion after blunt trauma with ecchymosis and some soreness over tendon following a recent lacrosse injury.
Q1 – A partial biceps tear is one of your top considerations, but is it the right call in this case?
A1 – This patient’s biceps and triceps are intact (see axial T2 GIF), so a partial biceps tear is not the right call. This is a grade 1 pennate architectural myotendinous unit tear (image 1, green arrows) of the brachialis muscle. The brachialis is located underneath or deep to the biceps muscle. It originates at the humerus near the insertion of the deltoid muscle on the anterior surface of the humerus distal one-half, inserts at the coronoid process and tuberosity of ulna, and serves as an important elbow flexor. It is not as well-known as the biceps in popular culture, but it is often the site of athletes’ injuries, especially after high-grade elbow dislocations. Innervated by the musculocutaneous nerve, it may have accessory slips or two “double muscle bellies.”
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