Long Head of Biceps Injuries
What is the anatomy of the biceps tendon and muscle?
The bicep muscle is well known to most people as the muscle that forms that shape of the anterior (front) surface of the upper arm and is often the prominent muscle on flexing the elbow. It is more prominent in males because muscle hypertrophy (bulk) is greater in a male’s anatomy due to the level of testosterone, but with the increase in prevalence of weight training in females, the biceps tendon/muscle is easily visualised on the thinner and fitter lady. The muscle starts from two points in the shoulder. The main attachment is the bone known as the coracoid (attached to the front of the shoulder blade) with another attachment (known as the long head of biceps tendon) running through the shoulder joint and starting at the top of the socket of the shoulder (called the supraglenoid tubercle). The 2 muscle tendons then join into the bulk of the muscle and then attach down in the front of the elbow to the proximal (uppermost) radius bone in the forearm.
Most people consider its function to be a flexor of the elbow but in reality, other muscles tend to do this and its main function is to turn the forearm into an upward position (the position which you place the hand in to receive money, also known as supination).
Where can tendon tears occur?
The most common tendon tear is at the long head of biceps proximally (in the shoulder) while the second most common region is distally (where it attaches to the elbow). Muscle belly tears can also occur.
The least common is that of coracoid tendon tears, which commonly involves a fragment of bone pulling away with it at the site (a coracoid fracture). We will restrict our discussion to the two most common sites, the long head of biceps or the distal biceps tendon.
Long head of biceps tears (at shoulder)
Tears of the long head of the biceps, at the shoulder, are very common. They especially occur with age, as the tendon degenerates. It will often present with several months of increasing pain around the shoulder before a sudden onset of more pain, bruising and then swelling. Often there is the development of more prominent biceps but which appears distally (further down the arm) to where the normal biceps muscle appears. People are often concerned by the lump thinking it is something sinister, but it is the bunched up muscle moving further down the arm.
A few weeks after the tendon tears, the pain often improves.
The two issues with this condition are:
- The cosmetic changes, including the deformity of the biceps which leads to a lump distally, known as a Popeye Sign.
- Concern about weakness that the person may develop.
Whilst proximal bicep tendon tears often result in a cosmetic abnormality, there is no loss of physical function.
There is a large amount of evidence that weakness is not an issue; there is no evidence that patients who have suffered a long biceps tendon tears are weaker. In fact, often after the tear, the pain the patient was experiencing before the tear has reduced. With this, the strength improves.
One option for treatment is to treat the initial pain, reassure the patient and let the arm settle. The alternative is to repair the biceps tendon. Please note that a long head of biceps tendon repair is not a true repair as it does not involve reattaching it to where it came from (which is through the shoulder joint and at the top of the socket). Instead, the biceps tendon is tensioned and re-attached to either soft tissue or bone below the shoulder joint, bypassing the shoulder joint.
Surgery may be performed if the patient is unwilling to accept the cosmetic abnormality, or if there are other factors that may warrant surgical intervention, such as a rotator cuff tear or pain from AC joint arthritis. In these cases, consideration will be undertaken to tenodesing (retensioning) the long head of biceps at the same time.
Surgery would involve an arthroscopic debridement ( decompression ) of the bursa of the shoulder and repairing the rotator cuff, and the long head of biceps may also be retensioned.