Distal Biceps Tendon Repair Using a Unicortical Button

Distal biceps tendon ruptures occur most commonly in the dominant arm of men in their 4th through 6th decades of life. These injuries lead to a 30% reduction in flexion strength and 40% reduction in supination strength. Numerous methods exist for fixation of the distal biceps tendon, including bicortical endobutton, transosseous tunnels, suture anchors, and interference screws. We review the technique for using a unicortical button fixation method.

Indications for surgical fixation of the distal biceps tendon include complete tendon ruptures, where a loss of elbow flexion and forearm supination strength of 30% and 40%, respectively, is not desired and partial tendon ruptures that have failed nonoperative treatment. Typically, nonoperative treatment of partial tendon ruptures is tried for a minimum of 3 months.

We present the technique of repairing a distal biceps tendon rupture using a unicortical button. A 1-incision technique is utilized through a transverse incision approximately 3-4 cm distal to the elbow flexion crease. Onlay fixation of the distal biceps tendon to the radial tuberosity is achieved with a unicortical, or intramedullary, button. The postoperative protocol varies with surgeon but is similar to other fixation techniques.

Outcomes for primary repair of the distal biceps tendon are promising in the literature with both patient-reported outcomes and objective data showing good to excellent results. Bicortical button fixation has traditionally shown to be stiffer with a higher load to failure than other fixation techniques, including suture anchors, transosseous tunnels, and interference screws. The unicortical button has been shown to be statistically equivalent to the bicortical button, with similar cyclic loading and load to failure values.

The unicortical button technique for distal biceps repairs has the benefit of using a small footprint in the radial tuberosity, potentially decreasing the risk of heterotopic ossification, providing a safer avenue of obtaining anatomic placement and trajectory of repair, and decreasing the risk of posterior interosseous nerve injury. The unicortical button has been shown to have a similar strength profile to the bicortical button, which is higher than all other fixation techniques previously described in the literature.