Pretest

Introduction

Disruption of the distal biceps brachii tendon is a relatively rare injury. Rupture classically occurs in the dominant extremity of men in the fourth to sixth decade of life, following a violent, eccentric contraction. It can be associated with smoking and steroid use. Although uncommon, distal biceps tendon injury is not without consequences. Rupture results in a 40% loss of supination strength, up to a 47% loss of supination endurance, and a 21% to 30% loss of flexion strength at the elbow when compared to the uninjured extremity.^1,2

When indicated, surgical repair has been accomplished by a variety of techniques, consisting of anatomic reinsertion of the biceps tendon to the ulnar aspect of the radial tuberosity. Surgical approaches include the classic one-incision, two smaller incisions, and a two-incision technique. Fixation to the radial tuberosity can be accomplished with a variety of devices including suture anchors, interference screws, or an EndoButton (Smith and Nephew, Andover, Mass).

Chronic cases occur after failed conservative management, when the injury goes undiagnosed, or after a high-grade chronic partial tear. Over time, the native tendon retracts proximally, scar tissue forms, and anatomic repair becomes difficult. Surgical reconstruction techniques in these situations require augmenting the distal biceps repair with either autograft (commonly semitendinosus) or allograft (commonly Achilles or fascia late femoris) tissue.

This tutorial focuses on the various surgical techniques in regard to anatomic re-insertion of the distal biceps tendon to the radial tuberosity in acute and chronic cases. (The clinical and radiographic findings consistent with the diagnosis of distal biceps tendon ruptures are described elsewhere in the Hyperguide.)

Applied Anatomy

The distal biceps tendon inserts on the ulnar aspect of the radial tuberosity in a ribbon-like fashion. The tendon insertion occupies approximately 14 mm (63%) of the length of the tuberosity and 2 mm (13%) of the width.³ Visualization of this site on the radial tuberosity is vital to enhance the correct anatomic location for repair or reconstruction of the distal biceps tendon.

Physical Examination

Acutely, distal biceps tendon ruptures present after a violent eccentric contraction of the dominant extremity. Patients complain of pain in the antecubital fossa, and associated swelling and ecchymosis on the medial aspect of the elbow and proximal forearm. A palpable antecubital defect, worse with elbow flexion, is classic. Physical examination may demonstrate weakness in supination and flexion, although this may be limited by pain.

Radiographic Findings

Radiographic imaging may occasionally show bony changes at the radial tuberosity, or a radial tuberosity avulsion consistent with this diagnosis. Magnetic resonance imaging (MRI) is indicated if the diagnosis is in question, in chronic cases to evaluate the amount of retraction of the muscle belly, and to aide in the planning of surgical reconstruction options. Occasionally, an MRI will show a partial tear of the distal biceps tendon.

Surgical Indications

Operative treatment is indicated in patients who will not tolerate the resulting functional deficits of a distal biceps tendon rupture described above. High-demand athletes, weight lifters, and laborers are ideal candidates for distal biceps tendon surgery. Even patients with partial tears may be candidates for surgical repair based on demonstrated functional deficits with partial distal biceps ruptures.

Surgical Approaches: One Incision vs. Two Incisions

Two operative approaches have been described. The one-incision anterior approach was the initial approach utilitized for distal biceps tendon repair. Historically, this had been described as a more extensive approach, with a higher risk of posterior interosseous nerve injury. With the introduction of various fixation devices such as suture anchors, this approach has been modified to a smaller incision, minimizing the amount of dissection necessary around the radial tuberosity, and thus less risk to the radial nerve.

The two-incision technique, initially described by Boyd and Anderson,⁴ avoids radial nerve damage but has been associated with heterotopic ossification, leading to radioulnar synostosis. Morrey² described a limited periosteal dissection and thus decreaed risk of this potentially disastrous complication.

Finally, Kelly and O'Driscoll⁵ have described a one-incision posterior technique. This technique is useful in the rare instance of a partial tear of the distal biceps tendon.

Single-Incision Anterior Technique

For the single-incision anterior techniques, the patient is placed supine, a sterile tourniquet is placed on the operative extremity, and the elbow is extended onto a radiolucent hand table. An oblique, curvilinear incision is made proximal to the flexion crease, medial to the biceps tendon, coursing over the flexion crease and ending distal and lateral if necessary. Alternatively, a straight transverse incision can be made over the flexion crease, with the option of extending the incision laterally at the distal aspect of the incision. In chronic cases, a longer curvilinear incision is made coursing from proximal lateral to distal medial.

The lateral antebrachial cutaneous nerve is identified with blunt dissection and retracted laterally. The distal biceps tendon stump is identified proximally via palpation. At times, the lacertus fibrosus remains intact, and the tendon is minimally retracted. The biceps bursa is incised, revealing the torn biceps tendon stump. A clamp is placed on the distal aspect of the torn tendon. Mobilization of the torn biceps tendon and the biceps brachii muscle belly via meticulous blunt finger dissection is vital to obtaining maximum excursion of the tendon. This is particularly important in chronic cases with severe tendon retraction.

Once the tendon stump is visualized, mobilized, and debrided, a tag suture can be placed in the tendon while the radial tuberosity is exposed. When ready, a #2 high-strength locking stitch is placed into the distal tendon. For the distal dissection, the forearm is kept supinated to protect the posterior interosseous nerve and to enhance visualization by delivering the radial tuberosity into the wound. The brachioradialis is retracted laterally and the pronator teres is retracted medially. The radial tuberosity is identified and soft tissue is bluntly dissected with the arm remaining in a supinated position. The cortex of the ulnar aspect of the tuberosity is initially prepared, usually with a high-speed burr. The amount and type of decortication of the radial tuberosity depends on the type of fixation planned for re-insertion of the distal biceps tendon.

Two-Incision Technique

For the two-incision technique, the patient is placed supine, a sterile tourniquet is placed, and the arm is prepped and draped in an extended and supinated position on a hand table. A 4-cm curvilinear incision is made anteriorly in similar fashion as the one-incision technique. Alternatively, a transverse incision over the antecubital crease can be used. The lateral antebrachial cutaneous nerve is identified, and the distal end of the stump is identified via blunt dissection. A #2 high-strength suture locking stitch is placed into the distal tendon. Using a curved clamp, the interosseous space between the radius and ulna is identified. With the arm flexed and pronated, the clamp is inserted through this area, tunneled through, and palpated distally over the proximal lateral forearm. A 1-cm longitudinal incision is made over the posterolateral elbow in line with the clamp. The extensor musculature may be elevated bluntly or split with the forearm remaining maximally pronated. The muscle-splitting approach limits subperiosteal dissection around the ulna, decreasing the risk for radioulnar synostosis.⁶ At this point, the ulnar aspect of the radial tuberosity is visualized, and the cortex is prepared with a burr. The forearm is then flexed and maximally supinated. The tendon is passed from the initial anterior incision, through the tunneled area between the radius and ulna, into the radial tuberosity, and fixed via the posterior incision.⁷

Acute Surgical Options: Repair Techniques

Various techniques have been described for anatomic re-insertion of the biceps tendon to the ulnar aspect of the radial tuberosity. Anatomic repair can be accomplished via a transosseous bone tunnel, with the use of suture anchors, interference screws or an EndoButton (Smith & Nephew).

Morrey² described the transosseous technique in conjunction with the two-incision approach. The technique consists of burring an initial trough in the proximal cortex of the radial tuberosity. Three 2.0-mm drill holes are placed through the trough into the far cortex, the sutures of the distal tendon are pulled through the far holes, the tendon is passed from anterior to posterior into the trough, and the sutures are tied to the posterior cortex with the elbow flexed 90° and supinated.

In the suture anchor technique, the arm is held in 90° of flexion and full supination. A burr is used to decorticate a window in the ulnar aspect of the radial tuberosity, and the anchors are placed in the most distal and proximal aspects of the tuberosity. The nonabsorbable sutures are then tied to the biceps tendon in sliding fashion, the tendon is pulled into the decorticated tuberosity and locked into place.⁸

The anterior one-incision approach is utilized for the use of the interference screw and EndoButton fixation. In the interference screw technique, a running locked stitch is placed into the tendon stump, an 8-mm tunnel is drilled from anterior to posterior, and the biceps tendon is placed into the tunnel. The tendon is secured to the tuberosity with an interference screw, with the sutures tied over the screw to provide additional fixation.⁹

In the EndoButton technique described by Bain and collegues,¹⁰ mini-C-arm fluoroscopy is recommended. A #2 or #5 high-strength suture is sutured into the tendon stump and secured to the EndoButton. The arm remains extended and fully supinated, a guidepin is placed into the ulnar aspect of the tuberosity from anterior to posterior. A 6-mm to 8-mm reamer is placed along the proximal cortex, without disrupting the distal cortex. The cannulated EndoButton drill is used to violate the posterior cortex, and the suture passing guide pin is directed out the posterior cortex through the skin. Suture is then placed into the EndoButton for passage through the posterior cortex. The leading end is pulled into the posterior cortex with the assistance of the guide pin. As the guide pin is passed through the skin, the EndoButton is flipped and secured onto the posterior cortex of the radial tuberosity, with the tendon stump secured into the cortical window.¹¹

Chronic Surgical Options: Reconstructive Techniques

The majority of distal biceps tendon ruptures that are surgically treated are fixed in the acute setting. Chronic cases occur as the diagnosis is missed or conservative treatment is not tolerated. This is a surgical challenge as the tendon retracts proximally and copious scar tissues forms.

Autograft tissue (e.g., semitendinosus tendon) and allograft tissue (e.g., tensor fascia lata, semitendinosus, or Achilles) have been used to augment reconstruction. The choice of supplemental fixation depends on patient preference, surgeon comfort with the procedure, as well as availability of allograft tissue.

Regardless of which surgical approach is chosen, the anterior incision will be extensile. Great care must be taken as this incision is extended proximally to bluntly dissect away scar tissue, visualize the lateral antebrachial cutaneous nerve, and mobilize the thickened, fibrotic proximal stump of the biceps tendon. Occasionally, a neotendinous stump may form, which should be debrided down to healthy tendon.

After dissection and mobilization of the biceps tendon stump, the length of graft necessary to reach the radial tuberosity is measured, and the semitendinosus autograft is harvested or the allograft is thawed. The graft material may be interwoven into the distal stump of the biceps tendon and then fixed to the radial tuberosity. Alternatively, the distal portion of the graft material may be fixed to the radial tuberosity, passed retrograde, and then sutured to the remaining distal biceps tendon stump with the arm flexed to approximately 40° and the elbow supinated fully.¹²

Postoperative Care

Patients are immediately splinted with the elbow flexed at 90° and maximally supinated. At approximately 10 to 14 days, the splint is removed, and gentle range of motion is begun. The severity of the injury and the difficulty of the repair dictate the postoperative physical therapy regimen. Range of motion, particularly full extension, should be achieved by 4 weeks, strengthening exercises begun at 6 weeks, with full return to activity at 3 to 4 months. In chronic cases treated with supplemental fixation, these parameters may be modified.

Results

Multiple repair techniques of acute distal biceps tendon tears have been reported in the literature. Morrey and colleagues,² McKee and researchers,⁸ and Bain and coworkers¹⁰ have reported excellent clinical results (between 82% and 96% restoration of flexion and supination strength) when repairing the distal biceps tendon to the radial tuberosity while using a transosseous technique, suture anchor technique, or EndoButton technique. The EndoButton has been shown in multiple studies to be stronger than the other fixation devices.^11,14 Mazzocca and collegues,⁹ in a recent biomechanical study, reported that the EndoButton had the highest load to failure when compared to suture anchors, interference screws, and the transosseous technique.

In chronic cases, many times repair is not possible, and reconstruction is augmented with the use of autograft or allograft tissue. The use of autologous semitendinosus tendon,^14,15 tensor fascia lata, and Achilles allograft¹² has been reported, as well. In these small series, postoperative flexion strength and supination strength have been reported as high as 90% of normal, or "comparable" to normal.

Discussion

The functional deficit that occurs in distal biceps tendon rupture is a decrease in elbow flexion strength, forearm supination endurance, and forearm supination strength. Anatomic reattachment of the distal biceps tendon to the radial tuberosity has been described via multiple surgical approaches and various surgical techniques. In chronic cases, allograft or autograft material is usually necessary to augment repair. When a well-informed patient decides on surgical intervention for a distal biceps tendon rupture, the surgeon should be familiar with these surgical approaches, fixation devices, and graft options.

References

1. Baker BE, Bierwagen D. Rupture of the distal tendon of the biceps brachii. Operative versus non-operative treatment. J Bone Joint Surg Am. 1985; 67:414-417.
    
2. Morrey BF, Askew LJ, An KN, Dobyns JH. Rupture of the distal tendon of the biceps brachii. A biomechanical study. J Bone Joint Surg Am. 1985; 67:418-421.
    
3. Boyd HB, Anderson LD. A method for reinsertion of the distal biceps brachii tendon. J Bone Joint Surg Am. 1961; 43:1041-1043.
    
4. Mazzocca AD, Cohen M, Berkson E, et al. The anatomy of the bicipital tuberosity and distal biceps tendon. J Shoulder Elbow Surg. 2007; 16:122-127.
    
5. Kelly EW, Steinmann S, O'Driscoll SW. Surgical treatment of partial distal biceps tendon ruptures through a single posterior incision. J Shoulder Elbow Surg. 2003; 12:456-461.
    
6. Kelly EW, Morrey BF, O'Driscoll SW. Complications of repair of the distal biceps tendon with the modified two-incision technique. J Bone Joint Surg Am. 2000; 82:1575-1581.
    
7. Morrey BF. The Elbow and Its Disorders. 3rd ed. Philadelphia, Pa: W.B. Saunders; 2000:933.
    
8. McKee MD, Hirji R, Schemitsch EH, Wild LM, Waddell JP. Patient-oriented functional outcome after repair of distal biceps tendon ruptures using a single-incision technique. J Shoulder Elbow Surg. 2005; 14:302-306.
    
9. Mazzocca AD, Burton KJ, Romeo AA, et al. Biomechanical evaluation of 4 techniques of distal biceps brachii tendon repair. Am J Sports Med. 2007; 35:252-258.
    
10. Bain GI, Prem H, Heptinstall RJ, Verhellen R, Paix D. Repair of distal biceps tendon rupture: A new technique using the EndoButton. J Shoulder Elbow Surg. 2000; 9:120-126.
     
11. Greenberg JA, Fernandez JJ, Wang T, Turner C. EndoButton-assisted repair of distal biceps tendon ruptures. J Shoulder Elbow Surg. 2003; 12:484-490.
     
12. Sanchez-Sotelo J, Morrey BF, Adams RA, O'Driscoll SW. Reconstruction of chronic ruptures of the distal biceps tendon with use of an achilles tendon allograft. J Bone Joint Surg Am. 2002; 84:999-1005.
     
13. Morrey BF. The Elbow. Master Techniques in Orthopaedic Surgery. New York, NY: Raven Press; 2000:349.
     
14. Hallam P, Bain GI. Repair of chronic distal biceps tendon ruptures using autologous hamstring graft and the EndoButton. J Shoulder Elbow Surg. 2004; 13:648-651.
     
15. Hang DW, Bach Jr BR, Bojchuk J. Repair of chronic distal biceps brachii tendon rupture using free autogenous semitendinosus tendon. Clin Orthop Relat Res. 1996; 323:188-191.