EndoButton-assisted repair of distal biceps tendon ruptures

Abstract

This report represents a multifactorial investigation of a new technique in which a titanium EndoButton was used for repair of distal biceps tendon ruptures. Cadaveric cases were used to demonstrate the anatomic efficacy and safety of the procedure. Biomechanical testing was done to compare the fixation strength of traditional techniques with the EndoButton repair. Finally, clinical results of the repair were evaluated. In 15 fresh-frozen cadavers the mean distance of the button from the posterior interosseous nerve was 9.3 mm. Instron testing showed a mean pullout strength of 253 N for the Mitek G4 Superanchor, 177 N for a conventional bone bridge, and 584 N for the titanium button. The button was 3 times stronger than the bone bridge (P =.0001) and 2 times stronger than the Mitek anchor (P =.0007). Fourteen patients who had their tendons repaired by this technique were evaluated at a mean of 20 months postoperatively. BTE (Baltimore Therapeutic Equipment, Baltimore, MD) testing revealed recovery of 97% of flexion strength and 82% of supination strength. Patients were able to participate in an aggressive rehabilitation program and were able to regain strength and function rapidly, with satisfactory return to preinjury activities and occupations. This technique is safe, simple, and stronger than any currently available anchoring techniques and gives the surgeon a choice in bone preparation. By using a single anterior elbow approach, the development of synostosis associated with two incision techniques can be minimized.