Functional Impacts of the Endobutton Technique in Distal Biceps Tendon Repair

Background Distal biceps tendon rupture is an uncommon injury that can result in significant impairment of elbow flexion and forearm supination. Surgical repair is commonly recommended for active patients, with a range of fixation techniques described. While bicortical Endobutton fixation (BEF) has demonstrated favourable biomechanical properties, clinical data describing functional recovery over time remain limited. Methods This retrospective case series evaluated ten patients who underwent distal biceps tendon repair (DBTR) using a single-incision anterior approach with BEF. Isometric elbow flexion and radioulnar supination strength were assessed at 3 and 12 months post-operatively using a dynamometer and compared with the contralateral, uninjured limb. Post-operative complications were recorded. Results At three months post-operation, both flexion and supination strength of the repaired limb were significantly reduced compared with the contralateral limb. By 12 months, flexion strength demonstrated substantial recovery and was no longer significantly different from the control limb, whereas supination strength remained significantly reduced. Mean flexion strength relative to the contralateral limb improved from 68.34% to 92.77% between 3 and 12 months, while mean supination strength improved from 48.81% to 69.89%. Two (20%) patients experienced transient neuropraxia, with no tendon re-ruptures observed. Conclusion DBTR using a BEF technique resulted in progressive functional recovery over 12 months. Elbow flexion strength demonstrated substantial recovery within the first post-operative year, while recovery of forearm supination strength was slower and less complete. These findings may assist with rehabilitation planning and patient counselling regarding expected functional outcomes following this technique.