What is the biceps tendon?
The biceps tendon is a long
cord-like structure which is located in the front of the shoulder. It
originates from the top of the shoulder socket (the glenoid) and exits the
joint through a bony trough (the biceps groove). Below the shoulder, this
tendon becomes the long head of the biceps muscle. The short head of the
biceps 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.
Who get biceps tendon injuries?
In general, these injuries
occur more frequently as we become older. As we age, our tendons lose
their elasticity and slowly become stiffer and more "brittle." The blood
supply which nourishes the tendon also diminishes with age. The
"degenerative" processes may be more pronounced in sedentary individuals,
but may be lessened with proper and regular exercise. The well conditioned
individual, however, is not immune from biceps tendon injuries as
over-training can also harm an otherwise healthy tendon.
How do biceps tendon injuries occur?
As mentioned above, age,
inactivity, or over-activity can weaken a tendon which may lead to injury
due to the decreased ability to endure repetitive motions and sudden
loads. Because of its location, from a direct blow to the front of the
shoulder. Some individuals develop bone spurs in their biceps grooves or
under the top of their shoulder blades (the acromion) which can lead to
wear and tear of their tendons. A less frequent injury is a dislocation of
the biceps tendon from its groove. This is usually seen in combination
with a tear of the subscapularis tendon or the rotator cuff tendon which
normally help hold the biceps tendon in it groove. The biceps tendon can
also be injured at its attachment site on top of the glenoid. This usually
involves an avulsion, where the tendon is pulled off the bone and rendered
unstable.
What happens to the tendon when it is injured?
If the tendon
or its sheath (which encases the tendon) is irritated, it becomes
inflamed, resulting in pain and swelling. This condition is called
"tendinitis." Mild injuries can also result in microscopic tearing of
individual tendon fibers. 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 a rupture occurs, the long head will usually fall
distally toward the elbow. Biceps muscle function usually remains nearly
normal because of its dual attachment proximally.
How are biceps tendon injuries treated?
Initially, rest, ice,
and gentle anti-inflammatory medications are all that is usually needed.
Sometimes an injection with a strong anti-inflammatory medication such as
cortisone is needed to control the pain and swelling. Severe cases which
fail to improve may require surgical treatment.
What does surgery involve?
Surgical treatment depends on the
nature and extent of damage to the tendon. If only a small portion of the
tendon is damaged, a simple arthroscopic shaving (debridement) of the torn
fibers may be all that is needed. If a significant portion is involved, a
biceps tenodesis may need to be performed. This is done by
arthroscopically removing the torn tendon stump from inside the shoulder
joint and then, through a small skin incision, attaching the remaining
tendon to the bone in the upper arm (humerus). If the biceps tendon is
completely rupture, causing the muscle to bulge in the upper arm, a
tenodesis can be done only if the distal portion remains near the top of
the shoulder. A tenodesis is not done if the tendon slides too far
distally because doing so would require unacceptably large incisions. If
the tendon has been partially avulsed from its origin on the top of the
glenoid (SLAP lesion), it can be arthroscopically reattached using
miniature screws and sutures
What is the usual course after surgery?
A simple sling is
all that is needed for the first few weeks after surgery. Immediate use of
the hand is encouraged, but only for very light objects. Four to six weeks
of healing is required before a gradual return to moderate or heavy
lifting. Desk work and light-duty can usually be resumed within the first
week or two. Return to heavy labor usually takes 2 to 4 months.
