ANATOMY (see shoulder anatomy)
The biceps muscle has 2 parts, the long head and the short head. The long head of biceps tendon arises from the top of the socket (glenoid) and passes within the joint exiting fromthe joint in the biceps groove and travels down to the biceps muscles (Fig. 1 and 2.)
This tendon moves up and down in the joint andthe groove when the shoulder is moved and is a common site of pathology. The short head of biceps tendon arises from the coracoid bone on the shoulder blade (scapula).
The biceps muscles attached to the radius in the forearm(conditions of that part of the biceps are discussed under the elbow section).
Biceps tendon may become inflamed due to overuse or an injury. This is a reversible condition and should resolve with anti-inflammatories or a cortisone injection into the groove. This injection is done under ultrasound guidance and more that one injection may be required to resolve the condition.
FRAYING OR PARTIAL TEAR
The biceps may tear partially or fray and be a source of pain.
Treatment initially is injections into the biceps groove which may lead to it rupturing spontaneously with resultant resolution of the pain. If it does not rupture, an arthroscopic tenotomy or tenodesis is done. In a tenotomy the tendon is simply cut and a ‘popeye’ deformity will occur in approximately a third of these patients. Alternatively the tendon may be sutured into the biceps groove and a deformity will not occur. The difference between these forms treatment is the recovery period.
With a tenotomy (cutting the tendon), the shoulder can be used almost immediately and most patients will be able to play sport within a month. However with a tenodesis (stitching the tendon in the groove) it will be 3 months before the patient can play sport. The tenodesis can be done by fixing the tendon into bone with a screw; in this case the arm can be moved earlier and the patient may get back to sport earlier.
Like the rotator cuff tendons, the biceps undergoes degenerative changes with age and may rupture with or without an injury. This usually occurs in older people who may or may not have experienced pain prior to the rupture. Once the biceps has ruptured the pain often disappears; if there is pain persisting after a rupture of the biceps, a tear of the rotator cuff tendons must be suspected.
With a rupture, the biceps muscle may shorten and have the appearance of a ‘popeye muscle’ (Figure 3). This is really a cosmetic deformity as there is minimal loss of power.
Most patients who rupture their biceps tendon are older and are not concerned about the cosmetic appearance of the muscle and do not lose much strengthen.
In a young patient or very active patient, one may consider a repair. This is done with an open operation whereby the biceps tendon is retrieved and pulled up and fixed into a hole in the humeral bone. This restores the length of the muscle and its appearance. Following this the patient is unable to flex the able up againat resistance for a period of 6 weeks.