Biceps Tendon Rupture
The biceps muscle has two origins; the short and long head of biceps. The short head of biceps inserts in to the tip of the corocoid process, which is a bony projection off the front of the shoulder blade (scapula). This is located outside the shoulder in contrast to the long head of biceps (LHB), which originates from within the shoulder joint itself.
The LHB passes over the humeral head (ball) within the shoulder joint and then exits the front of the shoulder and merges with the short head to form the biceps muscle. This continues down the front of the arm and inserts into the lower arm just below the elbow. The biceps muscle is responsible for elbow flexion and rotating the forearm such that the palm of your hand can face an upward direction (supination). However, the portion of the long head of biceps that passes within the shoulder joint also acts as a stabiliser to the shoulder.
As the long head of biceps lies within the shoulder joint it can be prone to a number of including Biceps tear or rupture. A normal long head of biceps tendon can rupture if it is suddenly overloaded when performing heavy lifting however, it more commonly ruptures after it has undergone degenerative change and it is therefore often associated with associated rotator cuff disease. If the LHB ruptures it can result in the LHB tendon becoming more prominent in the upper arm such that it is called a ‘Popeye Sign”.
Anterior shoulder pain, often extending down the front of the arm, is the main symptom associated with long head of biceps pain. If this persists, and further degenerative changes occur within the tendon, it can rupture. Often, following the rupture of the LHB, the bicipital pain that was experienced immediately prior to the rupture immediately settles. Bruising may be seen in the mid and upper arm and a “Popeye sign” may develop. This is where the ruptured long head of biceps tendon bunches up in the front of the arm, becoming particularly noticeable when the biceps muscle contracts, thereby resulting in the “Popeye sign”.
Causes & Risk factors
- Pre-existing rotator cuff degenerative changes
- Biceps tendonitis
- Biceps instability
- Frequent use of the arm at, or above shoulder height
The diagnosis is based on a clinical examination which may be supplemented with either an ultrasound or MRI scan to gain further information about the quality of the long head of biceps and its surrounding rotator cuff tendons.
The options for the treatment of a long head of biceps tendon rupture include;
- Conservative treatment comprising of rest, activity modification and the use of anti-inflammatory medications. As 90% of biceps function is achieved from the short head of biceps tendon, the loss of the LHB does not impact significantly on biceps or arm function.
- Biceps tenodesis; in this procedure the long head of biceps is retrieved from the upper arm and then reattached to the humerus just outside of the shoulder joint. Although this procedure can occasionally be performed as an arthroscopic procedure, usually the ruptured biceps retracts down into the upper arm and therefore the surgery must be undertaken as an open operation. If there is an associated rotator cuff tendon tear then a rotator cuff repair might also be needed. The nature of the rotator cuff repair operation would be dependant on the location and the size of the rotator cuff tear.