Biceps Tendonitis and Instability
The biceps has two heads, or muscle bellies, each with its own proximal tendon. The two heads join in the middle of the arm forming one distal tendon which inserts into the radius at the elbow.
The short head originates from the chest wall and is far more robust than the long head of biceps. This head provides for most of the function of the biceps muscle.
The long head originates from along tendon which is attached to the top of the socket of the shoulder (the glenoid). It runs through the shoulder to the upper arm and joins with the muscle belly of the short head of biceps. The long head of biceps is not required for normal shoulder function in most people except those involved in heavy, repetitive and overhead lifting.
Biceps tendonitis and Instability relates to the Long head of biceps tendon.
Biceps tendonitis is a cause of anterior shoulder pain often with radiation down the biceps muscle.
It may be primary i.e. inflammation in the bicepital groove with no other associated shoulder pathology (5% of cases) or secondary to some other shoulder pathology (e.g. rotator cuff tear and is much more common) with damage and fraying to the tendon and subsequent inflammation and pain.
Bicepital instability occurs with disruption of the bicepital pulley and subsequent subluxation and eventually dislocation of the tendon into the subscapularis muscle (anterior rotator cuff muscle). If this continues the subscapularis can sustain significant damage. Biceptal Instability symptoms are similar to bicepital tendonitis, but are often associated with a painful click as the tendon subluxes or dislocates.
Initial treatment is non operative, anti-inflammatory medications, corticosteroid injections and a rehabilitation programme directed at co-exiting shoulder pathology. If the patient remains symptomatic the operative treatment consists of releasing the biceps tendon from the top of the shoulder and fixing it in the bicepital groove, usually with a interference screw. This procedure is known as a biceps tenodesis, and is usually performed arthroscopically or arthroscopically assisted, with repair of any other associated shoulder pathology at the same time. The rehabilitation following such surgery is often 6 months.
In older and less active patients the biceps can be removed from the shoulder, a procedure known as a biceps tenotomy. The long head of biceps then scars up just below the shoulder and because the short head of biceps remains intact the biceps functions very well. There is usually a cosmetic deformity in the upper arm . This procedure has an easier recovery than a biceps tenodesis.
Non-operative treatment of Biceps instability is some what limited most patients remain symptomatic and as damage to the subscapularis muscle tend to be progressive patients usually require a biceps tenodesis and possibly a subscapularis repair depending on the appearance at the time of surgery. This is also usually performed arthroscopically.