Distal biceps tendon injury

Elbow

Distal Biceps Anatomy and Function

The biceps muscle, one of the muscles at the front of the upper arm bone (or humerus), has two muscle bellies, or heads, that have separate attachments on the shoulder. These attachments are located at the "proximal" end of the humerus. At the other end of the muscle, near the elbow, the two heads of the biceps join to form a single distal biceps tendon.

This tendon, located at the "distal" end of the humerus, inserts onto the radius bone, one of the two forearm bones. Through this distal insertion on the radius, the biceps is involved in both flexion and supination of the elbow. Supination is the act of turning the forearm from a "palm down" position to a "palm up" position, such as when tightening a screw with a screwdriver.
 

Distal Biceps Injury and Symptoms

Distal biceps tendon injuries can be partial or complete tears. They commonly occur on the dominant arm of middle-aged adults. Sudden loading of the tendon is a common mechanism of injury when the biceps muscle contracts but the elbow straightens quickly, such as when trying to catch a heavy object when it falls unexpectedly from a height. Usually, the injured tendon has some level of pre-existing disease or degeneration, called tendinosis, that makes it vulnerable to injury. People who smoke and those who are not physically active are more likely to rupture their biceps tendon when subjected to heavy loads.

Presenting symptoms of a distal biceps rupture include pain in the front of the elbow. Sometimes people with injuries report hearing a "pop" in the area. The pain usually subsides after the acute injury, and if left untreated, a chronic distal biceps tear is usually painless. There may be skin bruising in association with the injury.

If it ruptures completely, the tendon can pull back into the shoulder. If this occurs, a cosmetic deformity resembling a rounded mass may be noted in the lower biceps muscle. There may also be a hollow area in the elbow where the tendon used to attach. However, more often than not, there are not many noticeable changes in the appearance of the arm.

From a functional standpoint, some weakness will result in both flexion and supination, or rotation of the forearm. Supination is usually more affected than elbow flexion. However, multiple muscle groups are used in both movements and a deficit in functional range of motion will not occur. The other muscle groups can be strengthened to help compensate for non-functioning injured biceps. However, some residual weakness will be noticeable when lifting heavy objects or using a screwdriver, for example.

The diagnosis of a distal biceps rupture can usually be made on patient history and clinical examination. If there is a question of a partial injury to the tendon or concern about another associated injury (fracture, ligament injury, etc.), a magnetic resonance imaging (MRI) can be obtained.
 

How are distal biceps tears treated?

There are several options available for the treatment of a torn distal biceps tendon, ranging from conservative treatment to surgical interventions. Most patients will undergo surgery, but non-surgical treatment has a role in the person with low demand or in a patient who is not a good candidate for surgery. The treating orthopedic surgeon will discuss these options and help decide the ideal treatment based on the patient's demands, the physical examination, and the type of tear seen on imaging studies, including routine X-rays and MRIs. ).

A non-surgical physical therapy treatment program will often first focus on reducing pain and maintaining full motion of the elbow. Oral non-steroidal anti-inflammatory drugs (ie ibuprofen) may also be prescribed. After the initial injury, after pain has subsided and elbow movement is good, treatment can move to muscle strengthening of the other muscles around the elbow. Painless function with some residual weakness and early fatigue from supination can be achieved by conservative treatment.

Surgical management focuses on restoring the anatomy of the distal biceps tendon by repairing the tendon at its insertion site on the radius and allowing it to heal. Surgery is usually performed through an open incision at the front of the elbow or a two-incision approach, with a small incision at the front and back of the elbow.

Chronic ruptures are much more difficult to treat surgically, and sometimes grafts need to be used in this setting. For acute ruptures, the tendon can be reattached to the bone through a variety of techniques including sutures, surgical buttons, anchoring devices, and surgical screws.
 

Rehabilitation

After surgery, the elbow is usually immobilized for a few weeks and then gentle range-of-motion exercises are started. Most tendon healing is usually complete after two months, at which time light strengthening exercises can begin. Return to full activity is variable, but most patients can expect to return to their preoperative activities in 4 to 5 months.