Biceps Tendon and Superior Labrum Injuries
What is the biceps tendon?
The biceps tendon is a long cord-like structure, which is located in the front of the shoulder. The long head of the biceps tendon (LHBT) originates from the top of the shoulder socket (the glenoid) and exits the joint through a bony canal (the biceps groove). The short head of the biceps lies outside of the shoulder joint and is a continuation of the conjoined tendon, which originates from a bony hook (the coracoid) at the front of the shoulder blade. Thus, the biceps muscle, which functions to bend the elbow and rotate the forearm, has two anchor points in the shoulder region. The long head biceps tendon is the most commonly injured tendon of the shoulder. At its origin on the glenoid, the long head of the biceps is attached to the superior labrum, which is a continuous cartilaginous structure that surrounds the shoulder socket. Injury to the LHBT commonly occurs at the attachment point of the biceps on the labrum (biciptial-labral injury or superior labrum anterior to posterior (SLAP) tear).
How do biceps tendon and bicipital-labral injuries occur?
Most commonly, the biceps tendon is injured in patients who perform repetitive shoulder activities, such as contractors who use their hands overhead daily or athletes who routinely weight train. The biceps tendon is either injured at its attachment site on top of the glenoid (biciptial-labral injuries), where the attachment of the tendon to the superior labrum is pulled off the bone (SLAP tear). Additionally, the LHBT may be injured as it enters into the bicpital groove. Some older patients with shoulder arthritis may also develop bone spurs within the bicpital groove itself causing injury to the biceps tendon. Finally, the biceps tendon may also dislocate out of the groove, which is usually seen in combination with a tear of the subscapularis tendon of the rotator cuff.
What happens to the biceps tendon when it is injured?
If the tendon or its sheath (which encases the tendon) is irritated, it can become inflamed, resulting in pain and swelling (tendonitis). Mild injuries can also result in microscopic tearing of individual tendon fibers, which may cause pain with activity. As the severity of an injury increases, larger tears can occur to the point where the tendon is partially torn or even completely ruptured. If the injury occurs at the attachment to the labrum (SLAP tear), the tendon can remain relatively normal, but because the labral attachment is torn the patient will experience pain as the biceps tendon pulls on the labral tear. Despite these injuries, the function of the biceps muscle usually remains normal due to its dual attachment proximally at the shoulder.
How are biceps tendon injuries treated?
Initially, rest, ice, and anti-inflammatory medications are used to reduce swelling and inflammation. Sometimes, an injection with a steroid can be also used to reduce pain and swelling. For patients whose pain fails to improve with these conservative measures, surgery may be considered.
What does surgery involve?
Surgical treatment depends on the nature and extent of damage to the tendon or labrum. In younger patients (under 30-35 years of age), if the superior labrum is torn, it can be repaired arthroscopically (using a scope). Alternatively, patients over the age of 35 years of age with a superior labral tear, or patients with injuries to the biceps tendon that doesn’t involve the superior labrum, may be considered for a biceps tenodesis. A biceps tenodesis refers to releasing of the injured tendon from its origin on the glenoid and then reattaching the tendon to the bone in the upper arm (humerus). In patients over the age of 50-55 years of age, the long head biceps tendon may be simply released and not reattached (tenotomy). Since the biceps short head tendon is still intact, function of the biceps muscle is not affected.
What happens after surgery?
The patient is placed into a simple sling for the first few weeks after surgery. Following this, active range of motion is encouraged for the shoulder and elbow. Desk work and light duty can usually be resumed within the first week or two; however, weight bearing is restricted for three months following surgery.