The biceps muscle in the upper arm splits near the shoulder in a long head and a short head – both of which attach to the shoulder in different places. At the opposite end of this muscle is the distal biceps tendon, which connects to the smaller lower arm bone, the radius.
While all of these connections work to help the muscle stabilize the shoulder, allow for rotation of the lower arm, and adjust for accelerated and decelerated overhead movements, the long head of the biceps tendon is particularly vulnerable to injury because it travels through the shoulder joint to its attachment point.
If the long head of the biceps tendon is torn, arm strength is severely decreased and patients are unable to turn their arm from palm down to palm up. A bulge in the upper arm may also be evident, and, depending on the location of the tear, difficulty lifting overhead or bending the elbow may also be experienced.
Patients experiencing a rupture may hear a “snap” in the shoulder during an overhead movement, followed by shoulder aching and possibly upper arm bruising.
Those at Risk
A rupture may occur as part of a rotator cuff lesion in young athletes involved in rigorous overhead sports. In patients over the age of 50, a rupture near the scapular origin of the long head of the biceps tendon is often seen after only minimal trauma – often the result of degeneration and history of shoulder stress.
A thorough patient history and physical examination will most likely confirm suspicions. A special X-ray (arthrogram), or magnetic resonance imaging (MRI) may be indicated for patients with a history of shoulder pain in order to verify the condition of the rotator cuff muscles.
Conservative nonsurgical treatment is effective in addressing these types of conditions. These may include; cold compression to reduce swelling, nonsteroidal anti-inflammatory drugs (NSAIDs), a period of rest and refrain from activity that aggravates the condition, and a rehabilitative exercise program designed to strengthen shoulder muscles.
When conservative treatment does not resolve the problem, or if the rupture was part of a rotator cuff lesion in a young athlete or involves a complete tear of the distal biceps tendon, surgery may be indicated in order to reattach the tendon to the bone. Rehabilitative and strengthening exercises begin shortly thereafter.