Distal Biceps Tendon Rupture

A couple months ago I ruptured my right distal biceps tendon. This means there is no longer a direct connection between my biceps — the large muscle in the upper arm — and my forearm. The remnant of that tendon has contracted 8 mm (about a third of an inch) upward, away from the elbow joint. I elected not to have surgery to correct this defect, and will live the rest of my life somewhat disconnected. (Not an altogether new experience!)

How Did This Happen? An ill-behaved chocolate Laborador Retriever got loose in the neighborhood, and ran after my Shetland Sheepdogs, Miso and Mochi. As the dog ran past me on the left, I reached over with my right arm, and grabbed its collar, pulling it toward me. The dog (50 - 75 pounds) continued running, across me to the right, rotating my right arm outward and hyper-extending it. I heard a clacking noise that felt like the two bones of my forearm (ulna and radius) knocking against each other. There was immediate pain. I thought I might have an avulsion fracture — a tendon pulls so sharply on a bone it breaks off that piece of the bone — or have ruptured the fascia (covering) of my biceps, because I felt the muscle bulging unnaturally.

I put ice on my elbow and elevated it. Since I seemed able to move my arm naturallly in all directions, I thought I'd escaped serious injury. By the next day however, there was extensive bruising on the inside of my right arm, from mid-forearm almost to my armpit. There was also a lot of swelling, and as a consequence, it was painful to move the arm. Nevertheless, bruising, swelling, and pain subsided with each passing day, and normal movement returned. (I only resorted to Ibuprofen twice.)

About a month later however, I noticed my biceps looked deformed when flexed (contracted). I saw my family physician who ordered X-rays. They were negative for fractures, but she referred me to an Orthopedist who ordered MRI (Magnetic Resonance Imaging) and made the final diagnosis.

What Causes This Injury? My description of the injury is common. Patients report their biceps was contracted, then their forearm rotated outward (supinated) and pulled. They commonly report hearing a snapping or popping sound. Bruising, and swelling are also common. The deformed shaped of the biceps on contraction is due to the absence of its tendon connection at the elbow. Without the elbow (distal) tendon to hold it in place, the contracted biceps is pulled toward the shoulder by the (proximal) tendon at its other end. Physicians can feel the absence of the distal tendon by pressing into the hollow where the forearm meets the upper arm.

There are also predisposing conditions, primarily tendons that are less flexible and strong, and more brittle. In other words, aged tendons. Men experience this injury more often than women, but this is probably due to them being active in different ways — like having the hubris to imagine they can pull a 75 pound weight travelling at 25 miles per hour to a sudden stop with one arm, and not letting go when they fail!

What Are the Consequences? Surprisingly, few. The biceps is such an obvious muscle, a big bulging contracted biceps is iconic of male strength. Nevertheless, its main use is to lift with the arm out-turned, or to apply clockwise torque: Screw in a light bulb, or operate a screw-driver. I can still lift things, as long as my right forearm does not turn outward. I can do "curls" and side-arm pullups at the gym. I can lift 5 gal. carboys of water (42 pounds) onto a dispenser in the kitchen. I'll buy a power drill.

What Is the Treatment? There are two choices: Do nothing and live with some limited motion, or surgically re-attach the tendon to the radial tuberosity. Surgery has the advantage of promising to restore complete use of the arm. It also has an infrequent, although not insignificant probability of making the condition worse. Where the tendon is re-attached, exostoses (benign outgrowths of bone) can occur. If these become extensive, those portions of the forearm bones can "fuse" together, possibly preventing forearm rotation. It would be difficult to type, for example. I already have some exostoses ("bone spurs"), so I judge myself more susceptible to this possibility than most.

For these reasons, I've elected not to have surgery, and to live with a relatively minor defect. I will never look like Arnold Schwartznegger, but I am going to continue weight-training and regular exercising.

And the next time I'm feeling particularly testosterone-laden, I'm going to try to remember discretion is indeed, the better part of valor. The dogs will look out for themselves.