Diagnosing Distal Biceps Tendon Rupture

NYU Langone doctors use a physical exam and imaging tests to determine whether you have a distal biceps tendon rupture.

The distal biceps tendon is a fibrous tissue that attaches the biceps, the muscle in the front part of the upper arm, to the radius bone in your lower arm, just below the elbow. A rupture in the distal biceps tendon can be full or partial. A full rupture, which is the more common, causes the tendon to completely separate from the radius. A partial rupture means some tissue remains attached to the bone.

A rupture in the distal biceps tendon is typically caused by injury or overuse. A rupture can occur after an unexpected force is placed on the biceps tendon when the elbow is bent, such as with catching or lifting heavy items. A rupture can also occur while performing biceps curls or pull-ups, weight lifting, or playing a contact sport.

A full distal biceps tendon rupture typically causes the biceps to pull toward the shoulder, causing loss of strength in the upper arm. You may also experience weakness when supinating, rotating your arm so that your facedown palm is now facing up.

People who perform physical labor typically find that the injury prevents them from lifting heavy items. Everyday tasks such as turning a doorknob, opening bottles, or using a screwdriver can also be difficult.

While distal biceps tendon ruptures are uncommon, they are most likely to occur in the dominant arm of men aged 40 to 60. The distal biceps tendon cannot grow back, making surgery necessary.

Symptoms of Distal Biceps Tendon Rupture

A distal biceps tendon rupture causes pain and swelling near the elbow that subsides a couple weeks after injury. You may hear a popping sound if the tendon fully detaches from the bone. A rupture may also cause bruising on the forearm and elbow. You may be unable to fully bend your elbow and may experience weakness when trying to rotate your arm. A full distal biceps tendon rupture usually causes the biceps muscle to move toward the shoulder, creating a bulge in the upper arm.

Diagnostic Tests for Distal Biceps Tendon Rupture

Our doctors are experts at diagnosing a distal biceps tendon rupture.

Physical Exam

During the physical exam your doctor may perform a hook test, in which he or she inserts a finger near your elbow and “hooks” it around the tendon. If the finger cannot be hooked, the tendon has completely detached from the bone. Your doctor may also ask about your symptoms at the time of rupture and assess weakness and your ability to rotate your arm. Typical symptoms include extensive bruising, severe pain, and a malformation at the place on your arm where the distal biceps ruptured.

Imaging Tests

An X-ray helps your doctor rule out any bone fractures that may be contributing to your symptoms. An MRI provides images of the biceps tendon that determine whether you have a partial or full rupture, where it’s located, and whether your biceps has moved toward your shoulder.