Use of the Endobutton in Repair of the Distal Biceps Brachii Tendon

Abstract

Rupture of the distal biceps tendon is a relatively uncommon injury. It typically occurs in middle-aged men who sustain a sudden force to a flexed arm. The resultant strong contraction of the biceps causes the tendon sheath to detach from the radial tuberosity. This injury represents only 3% of all injuries to the biceps tendon; 96% of such injuries involve the long head, and 1% involve the short head (1, 2). Several theories about predisposing factors have been postulated. These include avascularity of the tendon, mechanical impingement of the tendon with pronation of the forearm, degenerative changes within the tendon, and hypertrophic lipping of the anterior margin of the radial tuberosity, which can then cause a rent in the tendon (3, 4). Clinically, patients present with a history of a sudden force to a flexed arm and then a “pop.” They typically report immediate swelling in the antecubital fossa and a deformity of the biceps muscle. They also report significant weakness with flexion and supination of the arm. The diagnosis is usually very easy to make clinically but can be confirmed with magnetic resonance imaging. Nonoperative treatment has been attempted but has often led to continued weakness of the involved extremity, especially with supination (1, 5, 6). This weakness is frequently unacceptable to patients who are athletically active or who do heavy labor (7, 8). Therefore, surgical correction is commonly the treatment of choice. Many surgical techniques have been described in the literature (9–14). These techniques have varied mainly in the location of reinsertion of the tendon. Reattachment of the biceps brachii has been proposed, but this technique resulted in strength deficits with supination of the forearm (5). Most authors now recommend anatomic reattachment to the radial tuberosity (9–14). Initially, this was accomplished through a single anterior approach that required extensive volar dissection to expose the radial tuberosity (2). Several reports began to surface identifying injury to the radial and posterior interosseous nerves (5, 15). It was speculated that the injury was caused by the excessive traction required during the procedure. Boyd and Anderson (12), in an attempt to avoid this debilitative complication, described a two-incision technique to expose the radial tuberosity. Unfortunately, there have been subsequent reports of patients developing radioulnar synostosis following this procedure (16, 17). Several other techniques have also been reported, including the use of pull-out wires and external buttons (15, 18). As a result, alternatives to the two-incision technique and the anterior approach with extensive volar dissection have been proposed. Reattachment of the tendon utilizing suture anchors was reported by Barnes et al (11). This technique resulted in a high success rate without complications. However, this operation is not without difficulty. It requires the surgeon to work in a fairly deep wound with the elbow flexed to place the suture into the tendon. Tying of the sutures is also critical to ensure that the tendon is approximated to the bone. Bain et al (10) recently reported the use of the Endobutton for repair of the tendon. This procedure allows for a relatively minimal single anterior incision to reattach the tendon without struggling in a small space. This is a report of our use of the Endobutton in 11 patients who suffered rupture of the distal biceps tendon.