Biceps Tenodesis for Distal Biceps Tendon Repair

The annual incidence of distal biceps tendon ruptures is 1.5 per 10,000 per year. In 93% of cases, men aged 30–59 are involved, mainly in the dominant extremity. Distal biceps tendon ruptures can result in loss of supination and elbow flexion strength, for which surgical repair is often indicated to restore preinjury level of functionality. The distal biceps tendon can be repaired via single- or double-incision techniques using several associated implants, including endobuttons, suture anchors, or interference screws. Here, we present the case of a middle-aged male presenting with an acute distal biceps tendon rupture. The tendon was repaired via a single-incision technique using an endobutton and an interference screw. 

Distal biceps repair, single incision, double incision, endobutton, interference screw, suture anchor.

Distal biceps tendon tears have an annual incidence rate of 1.5 per 100,000 people, with the majority occurring in the dominant arm and in males.² Distal biceps tendon ruptures are typically multifactorial and include tendon degeneration, limited vascularity, and mechanical factors through repetitive trauma or eccentric contracture.³ The short and long head of the biceps comprise the distal biceps tendon attaching to the biceps tuberosity of the radius. The average area of the long head attachment is about 48 mm, and the short head is 60 mm. The primary action of the biceps is forearm supination, while the secondary action is elbow flexion. Thus, a complete distal biceps tear results in loss of supination and elbow flexion strength. Complete distal biceps tendon tears can be indicated for surgical repair in order to restore elbow flexion and forearm supination strength.¹

A complete distal biceps tendon tear presents with a sudden onset of sharp pain in the antecubital fossa, often with an audible pop, followed by ecchymosis and alteration in the ability to flex the elbow and supinate the forearm. There may be a history of a sudden eccentric force to a flexed elbow, such as heavy lifting. Unlike a proximal biceps tendon rupture that can result in shortening of the biceps musculature, often referred to as a “Popeye deformity”, a distal biceps rupture may be not as obvious of a shortening or retraction of the biceps muscle because the lacertus fibrosus may maintain continuity with the distal biceps tendon, minimizing tendon retraction. 

Findings on physical exam of a complete distal biceps tendon tear include: 

Retraction and ecchymosis: On inspection, swelling and ecchymosis are evident in the antecubital fossa, with possible shortening or proximal retraction of the biceps muscle.

Hook test: On palpation, the distal biceps tendon may not be palpable. A useful clinical test is the ‘hook test’ in which the elbow is flexed to 90 degrees, and the forearm is supinated. The examiner’s index finger is placed between the lateral edge of the biceps and brachioradialis (BR) to hook the finger around the tendon. Inability to hook indicates a complete distal biceps tendon tear because the distal brachialis is flat. The hook test is the most sensitive and specific physical examination test in diagnosing a complete distal biceps tendon tear.⁴ With a partial tendon tear, it may be able to hook the tendon, but it may be more painful.

Weakness: Resisted forearm supination on the injured side will be weaker and painful.

Ruland biceps squeeze test: With the elbow supported in 60–80 degrees of flexion and the forearm pronated, the biceps muscle is squeezed to elicit passive forearm supination. In the case of a rupture, the forearm will not supinate.⁵

Radiographs are taken to assess bony avulsion and other potential injuries. MRI is highly sensitive and specific in diagnosing a complete tear, with even 92% sensitivity and 85% specificity in diagnosing partial tears. The recommended position for the optimum visualization of the distal biceps tendon is elbow flexion, shoulder abduction, and forearm supination (FABS). In this position, the whole length of the tendon is visualized on a single cut.⁶ Ultrasound is also effective in diagnosing distal biceps tendon tears.

Non-operative treatment is a reasonable treatment strategy as pain improves after the acute period, but residual loss of forearm supination and elbow flexion strength with altered contours of the biceps musculature will persist. However, the rate of returning to the previous level of strength is greater with a surgical repair.⁸

Both partial and complete distal biceps tears can be treated non-operatively and operatively. If pain persists, loss of strength is symptomatic, and/or the altered biceps contour is unacceptable, surgical repair can be performed.⁹ 

Distal biceps tendon repair can be performed using single- or double-incision techniques. Studies have shown no significant difference in functional outcomes, force, and range of motion between the two techniques. The complication rates are comparable (24% in single-incision vs. 26% in double-incision techniques).¹⁰ 

Options to fixate the distal biceps tendon include suture anchors, buttons, interference screw, and the bone tunnel. Biomechanical studies have shown that button repairs provide the strongest repair compared to the other three, which are comparable. More robust repair and superior load to failure allow an earlier range of motion.¹⁰

The primary goal of distal biceps tendon repair is to restore and maximize functional recovery. Biomechanical analysis has demonstrated a 74% and 88% strength of supination and flexion, respectively, compared to the contralateral side following non-operative management.³ Another study has demonstrated that non-operative management of distal biceps tendon rupture results in 50% loss of sustained supination strength, 40% loss of maximal supination strength, 30% loss of flexion strength, and even 15% loss of total grip strength. In general, varying degrees of weakness may persist with non-operative treatment.³

Operative treatment is usually indicated in younger active patients preferring to maximize functional recovery.¹¹ Patients with low physical demands and/or several comorbidities may elect a conservative non-operative approach.

Clinical management of distal biceps tendon ruptures vary based on whether the tear is complete or partial and the patient's desired functionality outcomes. However, several studies supported surgical intervention because of increased supination and flexion strength.^3,6,10 Treatment of partial tears may include activity modification, physical therapy, and anti-inflammatory medications to decrease symptoms. 

In the presented case, the distal biceps tendon was repaired through a single incision.  A longitudinal anterior incision is made at the flexion crease and distally following the medial border of the BR. The lateral antebrachial cutaneous nerve is identified and protected, lying over the fascia and in proximity to the cephalic vein. The ruptured biceps tendon can be located within the antecubital fossa or retracted proximally. 

Once identified, the distal degenerated portion of the tendon is debrided, and a whip stitch suture is passed through the distal 2–3 cm of the tendon stump. The distal end of the tendon is debrided to fit the tunnel's diameter, which is ideally 7–8 mm in diameter. The distal 1 cm of the tendon is marked to help estimate the length of the docked tendon in the tunnel. A 2-0 silk shuttle loop is passed proximal to this marking to facilitate later shuttling of the suture to reinforce the repair. The free ends of the whip stitch are each passed through one eye of the endobutton and out the other. The tendon is now ready to be delivered into the tunnel.  

The bicipital tuberosity of the proximal radius is exposed by fully supinating the forearm after cauterizing or ligating the deep venous leash. With the forearm held in full supination, a guidewire aiming ulnarly to avoid the posterior interosseous nerve (PIN) is placed bicortically, and its position is confirmed on fluoroscopy. Next, a unicortical 7.5-mm drill hole is made over the guidewire. The bone debris should be irrigated thoroughly before the repair to lower the chance of heterotopic ossification. The button is passed through the tunnel with the insertion jig, deployed across the tunnel, and flipped on the far cortex by tensioning the suture limbs. The sequential pull of the two suture limbs delivers the tendon into the tunnel. This step is done with slight elbow flexion and full forearm supination until the marked line on the tendon disappears. One of the limbs is shuttled via the prepared shuttling silk suture and tied to itself, thereby securing the tendon in position. The tendon is reinforced within the tunnel by placing an interference screw across one suture limb. The suture limbs are tied once more over the interference screw. This repair construct includes three fixation points, endobutton repair, interference screw, and the final knot. The wound is irrigated and closed, and hemostasis is ensured. A posterior elbow splint is applied with the elbow at 90 degrees of flexion and the forearm supinated. Alternatively, a sling in 90-degree elbow flexion may also be sufficient. Postoperatively, the patient is started on protected range of motion and progressive strengthening on a graded basis. Unrestricted lifting can generally be permitted by three months postoperatively.¹²

A randomized controlled study that compared single-incision and double-incision techniques on acute distal biceps tendon tears found that both methods provided similar results in terms of pain, function, isometric extension, pronation, supination strength, and patient-rated elbow evaluation (PREE) score.¹³ Another study found that a double-incision technique resulted in 10% increased isometric flexion strength in comparison to the single-incision technique.¹⁴ Although complications are rare, one study with 53 patients reported one wound complication, two transient paresthesia of the lateral antebrachial cutaneous nerve, and one PIN palsy that resolved within six weeks.¹⁵ The overall prognosis after biceps tendon rupture repair is satisfactory.¹⁶ Factors such as comorbid disorders, concomitant injuries, age, and time from injury to surgery all play a role in outcomes and complications.

Measures of surgical efficacy can vary and may include:

• Time from injury to surgery
• Muscle force
• Grip strength
• Elbow flexion-extension
• Forearm supination-pronation
• Pain
• Elbow stiffness
• Heterotopic ossification with or without synostosis
• Nerve injuries

This equipment used in this procedure includes an Arthrex® button fixation system using the 12-mm BicepsButton™ from Arthrex® and #2 FiberLoop® with a straight needle and a PEEK Tenodesis Screw, 7 mm x 10 mm (Arthrex Inc, Naples, Florida).

Nothing to disclose.

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.