Posterior interosseous nerve incarceration with endobutton repair of distal biceps

Distal biceps ruptures are uncommon injuries that comprise approximately 3% of all biceps pathology. This injury is most commonly seen in 40-to 60-year-old men, and the mechanism of injury involves a forceful extension movement to a flexed elbow. Without surgical intervention, patients are left with measurable weakness in elbow flexion and supination as well as a cosmetic deformity that often leaves them dissatisfied. Consequently, early surgical repair is advocated for physically active individuals. A variety of surgical approaches and fixation devices are currently used for distal biceps repair. The single-incision cortical button repair for distal biceps avulsions has become popular since Bain introduced the technique in 2000. The advantage of the cortical button biceps repair technique is the significantly higher failure strength than either the 2-incision technique or the suture anchor repair. The initial repair strength of the cortical button technique allows immediate active elbow range of motion and accelerated rehabilitation. Additionally, the single-incision anterior approach is less invasive than the 2-incision biceps repair and results in a lower incidence of heterotopic ossification. One disadvantage of this approach, however, is the risk of injury to the posterior interosseous nerve. The authors report a case in which the posterior interosseous nerve was incarcerated between the cortical button and the radius during acute distal biceps repair, resulting in complete posterior interosseus nerve palsy. This case report details the surgery leading to the nerve palsy and the subsequent nerve exploration that identified the cause of the nerve palsy. Recommendations are made on how to avoid this complication during distal biceps tendon repairs.