The biceps has two origins, crosses the shoulder and elbow joints, and inserts on the proximal radius. The long head is much more susceptible to injury, and rupture may occur anywhere along its route. Clinically, patients with proximal rupture present with pain along the anteromedial aspect of the shoulder. On inspection, ecchymosis is often acutely noted. Muscle retraction within the arm may create a “Popeye” deformity. Due to the two proximal attachments, the short head of the biceps can allow for maintenance of forearm supination strength. Rupture may also occur at the tendon insertion into the radial tuberosity at the elbow. This diagnosis is made based on a history of a painful, tearing or popping sensation in the antecubital region. The ability to palpate the tendon in the antecubital fossa may indicate partial tearing.
Biceps Brachii Anatomy. (Reproduced with permission from Chow YC. Elbow and forearm injuries. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw Hill; 2016.)
Management and Disposition
Proximal and distal biceps tendon ruptures can be discharged with a sling, pain control, physical therapy, and referral for operative repair consideration. Distal biceps tendon ruptures often require surgical management due to the significant loss of forearm supination strength.
Functional deficits from a long head rupture are usually temporary and are influenced by coexistent tears.
Biceps rupture occurs most commonly in the dominant extremity of men between 40 and 60 years of age when an unexpected extension force is applied to the flexed arm.
The hook test is used to aid in diagnosis of distal biceps tendon rupture. The test is performed by having the patient flex elbow to 90 degrees and supinate forearm. Examiner uses their index finger and attempts to hook the lateral edge of the distal biceps tendon in the antecubital fossa. If tendon is unable to be “hooked,” there should be a high suspicion for tendon rupture (see video).
Distal Biceps Tendon Rupture. The tendon is noted to contract within the arm after rupture (A). Significant ecchymosis is seen in a different patient following distal biceps tendon rupture (B). The same patient in B had a normal hook test in the unaffected extremity (C) and an abnormal hook test in the affected extremity (D). See video. (Photo contributor: Alan B. Storrow, MD.)