Biceps tenodesis should preserve the length–tension relationship of the biceps muscle and maintain its normal contour. Tenodesis location may be proximal or distal. Proximal fixation can be performed arthroscopically, and its advocates argue that keeping the LHB tendon within the bicipital groove preserves muscle strength. Boileau and Neyton11 found biceps strength to be 90% that of the contralateral arm after arthroscopic tenodesis. The bicipital groove, however, is lined with synovium and is a primary site of LHB pathology. Up to 78% of intra-articular biceps tears extend through the groove outside the joint.12 Proximal tenodesis thus retains a major pain generator. In a retrospective study of 188 patients, Sanders and colleagues13,14 found a 36% revision rate after proximal arthroscopic tenodesis and a 13% rate after proximal open tenodesis with an intact biceps sheath—significantly lower than the 3% after distal tenodesis outside the bicipital groove.1 For this reason, we advocate distal biceps tenodesis beneath the pectoralis major tendon. After tenotomy with an arthroscopic basket (Figure 3), the LHB tendon is retracted out of the glenohumeral joint by extending the elbow. For the mini-open incision, the head of the bed is lowered from the beach-chair position to 30°. The arm is abducted on a Mayo stand, and the inferior border of the pectoralis major tendon is palpated. A 3-cm vertical incision is made along the medial arm starting 1 cm superior to the inferior pectoralis edge. The subcutaneous tissues are mobilized, and dissection is carried down to the pectoralis major and coracobrachialis tendons. Visualization of the cephalic vein indicates that the exposure is too far lateral. The horizontal fibers of the pectoralis major are identified, and a small incision through the inferior overlying fascia is directed laterally and then distally in line with the long axis of the humerus. Digital palpation helps identify the anterior humerus and fusiform LHB tendon running vertically within the intertubercular groove (Figure 4). Cephalad retraction of the pectoralis major allows direct visualization of the LHB tendon. A right-angle clamp is positioned deep to the LHB tendon and directed medial to lateral to retrieve the LHB tendon out of the incision.
No. 2 looped Fiberwire (Arthrex) is then whip-stitched from the top of the myotendinous junction up 20 mm (Figure 5). The remaining 2 to 3 cm of LHB tendon proximal to the whip-stitching may be excised to remove inflammatory tissue. The pectoralis major is retracted superiorly with an Army-Navy retractor while a pointed Hohmann retractor is placed laterally. Medial retraction of the conjoined tendon should be done carefully with a Chandler elevator and minimal levering. In a cadaveric study, Dickens and colleagues15 found that the musculocutaneous nerve, radial nerve, and deep brachial artery were all within 1 cm of the standard medial retractor. Compared with internal rotation of the arm, external rotation moves the musculocutaneous nerve 11 mm farther from the tenodesis site.15
Once exposure is adequate, the appropriate length–tension of the LHB tendon must be established. The inferior edge of the pectoralis major is used as a landmark. Anatomical studies have shown that the top of the LHB myotendinous junction lies 20 to 31 mm proximal to the inferior pectoralis edge.16,17 Therefore, the tenodesis site should be 2 to 3 cm superior to the inferior pectoralis edge and centered on the humerus. Overall, the subpectoral location offers unique landmarks for LHB length-tensioning and provides soft-tissue coverage of the tenodesis site.
After identification of the appropriate tenodesis site, the surgeon chooses from a variety of fixation techniques. The “bone-tunnel technique” involves drilling an 8-mm unicortical hole through the anterior humerus followed by 2 smaller suture tunnels inferior to it; the LHB tendon with Krackow stitches is passed retrograde through the large hole by pulling the sutures through the smaller tunnels and tying them down.18 Despite the ease of performing this type of fixation, Mazzocca and colleagues19 found more cyclic displacement with bone tunnels than with interference screws and suture anchors. Other, less common techniques include the keyhole method (passing a rolled knot of LHB tendon through a keyhole in the bone)20 and soft-tissue tenodesis to the rotator interval or conjoined tendon.21,22 Recently, however, attention has turned mostly to interference screw and suture anchor fixation.
Multiple laboratory studies have demonstrated the superiority of interference screw fixation. Kilicoglu and colleagues23 and Ozalay and colleagues24 evaluated various fixation types in a sheep model, and both groups found the highest loads to failure with interference screws. Patzer and colleagues25 compared interference screws and knotless suture anchors in a human cadaveric study and noted significantly higher failure loads with interference screws. Some authors26,27 have presented conflicting laboratory data, and Millett and colleagues28 reported no difference in clinical outcomes between interference screws and suture anchors. However, these studies have not demonstrated inferiority of interference screws, and, in light of other evidence suggesting its biomechanical superiority, we prefer interference screw fixation.19,23-25,29