A distal biceps rupture occurs when the tendon attaching the biceps muscle to the elbow is torn from the bone. This injury occurs mainly in middle-aged men during heavy work or lifting. A distal biceps rupture is rare compared to ruptures where the top of the biceps connects at the shoulder. It is estimated that distal biceps ruptures make up between three and 10 percent of all biceps tendon ruptures.
The biceps muscle goes from the shoulder to the elbow on the front of the upper arm. Tendons attach muscles to bone. Two separate tendons connect the upper part of the biceps muscle to the shoulder. One tendon connects the lower end of the biceps to the elbow.
The lower biceps tendon is called the distal biceps tendon. The word distal means that the tendon is further down the arm. The upper two tendons of the biceps are called the proximal biceps tendons, because they are closer to the top of the arm.
The distal biceps tendon attaches to a small bump on the radius bone of the forearm. This small bony bump is called the radial tuberosity. Surgery to repair the tear brings the torn end of the tendon back to the bump if possible. If the tear is too extensive and the arm has to be bent 70 degrees or more to bring the torn end back to the bone, then a tendon graft is used to extend the tendon long enough to reattach it to the radial tuberosity.
Many patients are content to let the torn tendon heal where it retracts (pulls back) to. Nonsurgical treatments are usually only used for people who do minimal activities and require minimal arm strength. Nonsurgical treatments are only used if arm weakness, fatigue, and mild deformity aren’t an issue. If you are an older individual who can tolerate loss of strength, or if the injury occurs in your nondominanat arm, you and your doctor may decide that surgery is not necessary.
Not having surgery often results in significant loss of strength. Flexion of the elbow is somewhat affected, but supination (which is the motion of twisting the forearm, such as when you use a screwdriver) can be very affected. A distal biceps rupture that is not repaired reduces supination strength by about 50 percent.
Many doctors prefer to treat distal biceps tendon ruptures with surgery and the sooner the better. If the patient experiences cramping, ongoing pain, or the loss of strength that affects daily function, then surgery is advised.
People who need normal arm strength get best results with surgery when the tendon is reconnected right away. Surgery is needed to avoid tendon retraction. Retraction occurs when the tendon has been completely ruptured and contraction of the biceps muscle pulls the tendon further up the arm. When the tendon recoils from its original attachment and remains there for a very long time, the surgery becomes harder, and the results of surgery are not as good.
You should rely on your surgeon to evaluate your situation and advise you on the best course of action for you. The extent of injury, time since the trauma, your personal and work goals, and level of activity will all help guide and direct the decision-making process.