Distal Biceps Tendon Repair Using a Unicortical Button

Abstract

Background:

Distal biceps tendon ruptures occur most commonly in the dominant arm of men in their 4th through 6th decades of life. These injuries lead to a 30% reduction in flexion strength and 40% reduction in supination strength. Numerous methods exist for fixation of the distal biceps tendon, including bicortical endobutton, transosseous tunnels, suture anchors, and interference screws. We review the technique for using a unicortical button fixation method.

Indications:

Indications for surgical fixation of the distal biceps tendon include complete tendon ruptures, where a loss of elbow flexion and forearm supination strength of 30% and 40%, respectively, is not desired and partial tendon ruptures that have failed nonoperative treatment. Typically, nonoperative treatment of partial tendon ruptures is tried for a minimum of 3 months.

Technique Description:

We present the technique of repairing a distal biceps tendon rupture using a unicortical button. A 1-incision technique is utilized through a transverse incision approximately 3-4 cm distal to the elbow flexion crease. Onlay fixation of the distal biceps tendon to the radial tuberosity is achieved with a unicortical, or intramedullary, button. The postoperative protocol varies with surgeon but is similar to other fixation techniques.

Results:

Outcomes for primary repair of the distal biceps tendon are promising in the literature with both patient-reported outcomes and objective data showing good to excellent results. Bicortical button fixation has traditionally shown to be stiffer with a higher load to failure than other fixation techniques, including suture anchors, transosseous tunnels, and interference screws. The unicortical button has been shown to be statistically equivalent to the bicortical button, with similar cyclic loading and load to failure values.

Discussion/Conclusion:

The unicortical button technique for distal biceps repairs has the benefit of using a small footprint in the radial tuberosity, potentially decreasing the risk of heterotopic ossification, providing a safer avenue of obtaining anatomic placement and trajectory of repair, and decreasing the risk of posterior interosseous nerve injury. The unicortical button has been shown to have a similar strength profile to the bicortical button, which is higher than all other fixation techniques previously described in the literature.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

My name is Gus Barrazueta. I am one of the hand and upper extremity fellows at Ohio State University, and I will be narrating this technique video on a distal biceps tendon repair using a unicortical button. This case was done in conjunction with 2 of our faculty members, Dr Gregory Cvetanovich and Dr Hisham Awan.

There are no pertinent disclosures related to this talk.

These injuries most commonly occur in the dominant arm of men in the 4th through 6th decades of life. It leads to a 30% reduction in flexion strength and 40% reduction in supination strength. There are numerous methods that exist to fix a distal biceps tendon. Indications for surgery include full tears where a loss of strength is not desired and partial tears that have failed nonoperative management. We present the technique of repairing the distal biceps tendon using a unicortical button. Outcomes for surgical repair are promising in the literature in both patient-reported outcomes and objective data.

Our patient is a 59-year-old man who presents with left elbow pain after feeling a “pop” when carrying boxes 5 days prior to presentation. Examination shows ecchymosis over the anterior elbow with the skin intact. Elbow flexion is 0-90° that is limited by pain. He has full pronosupination. However, he has pain with motion. There is tenderness over the distal biceps with no tendon palpated on the hook test. Surgical indications include full tears where loss of flexion and supination strength is not desired and partial tears that have failed nonoperative treatment for at least 3 months.

The hook test is a gold-standard physical examination maneuver to evaluate for distal biceps tendon avulsion. It was originally developed by Shawn O’Driscoll in 2007. It is performed by asking the patient to actively flex the elbow to 90° and fully supinate the forearm. In this position, the examiner then uses their index finger to hook the lateral edge of the biceps tendon. With an intact, or partially torn, tendon, the finger can be inserted 1 cm beneath the biceps tendon and hook it. If the tendon is completely ruptured, the examiner will not feel the cord-like structure to hook his or her finger under it.

Preoperative planning includes taking a good history and performing a good physical examination. A magnetic resonance imaging (MRI) is not necessary in all cases but can be helpful in confirming the pathology. If operating on a chronic rupture, you must have an autograft or an allograft available and be prepared to use it. This can be performed through either a 1-incision or 2-incision technique. There are many different techniques to actually fixate the tendon back to bone as well. We present a 1-incision technique using a unicortical button for fixation. Positioning includes placing the patient supine with the extremity on a hand or arm table.

Shown here are representative cuts of our patient’s MRI. They show a full tear of the distal biceps tendon with approximately 3.5 cm of retraction.

We begin with our incision. You can choose to do either a transverse or longitudinal incision. We choose a transverse incision centered approximately 3 finger breadths distal to the elbow flexion crease.

Here is a closer look at our incision. We begin by making our incision through the skin, including the deep dermis.

Here, we are dissecting through the subcutaneous tissues. In this plane, you will find a lot of veins. There are different strategies to getting through the veins. If you can find a window where you can retract the veins out of your way, you may certainly work through that window. However, more commonly, they are in the way so you have to either tie them off, as we are doing here, or use hemoclips to clip and cut them.

Here is our view of the biceps tendon after getting through all the venous structures in the subcutaneous tissues.

Here, we are grabbing the biceps tendon and bringing it into better view so we can see the torn end of the distal biceps tendon. It is important to debride this unhealthy tissue from a healthy tendon prior to repairing it.

Once you have a grasp of the distal biceps tendon, it is a good idea to free it up. We first do this with dissecting scissors by spreading around the tendon and manually with our finger, breaking up any further adhesions around the tendon.

Now we have the tendon all freed up. Freeing up the tendon is especially important in subacute or more chronic cases where the tendon has retracted and you are trying to get as much length as possible.

There are many different ways to secure the distal biceps tendon with sutures. Two of the most common techniques are using a running Krackow stitch or, what we chose to do here, is use a looped fiber loop in a looped-locking manner running down the tendon. Here, we are finishing up our running suture, and we have made sure to secure at least 3-4 cm of the distal biceps tendon with our fiber loop in a looped-locking fashion.

Here, we are sharply debriding the end of the tendon that does not appear to be healthy enough tendon for repair.

And this is our final prepared distal biceps tendon ready for reinsertion and repair.

Now, there are many different ways to secure and repair a ruptured distal biceps tendon. We will show you our technique of using a unicortical button. There are many advantages to using a unicortical button. It requires a much smaller drill hole than a bicortical button that puts the proximal radius at a theoretical decreased risk of fracture. The smaller drill hole also creates less debris that could in turn decrease the chance of heterotopic ossification formation. Because it is unicortical, you also essentially eliminate the risk of a posterior interosseous nerve (PIN) nerve injury. Because you are not worried about the PIN, you can now drill the hole in a more anatomic position without worrying about where your drill will end up on the other side of the bone. Using a button that slides also allows you to tension your repair appropriately. The unicortical button we use here is the same button that we use for a proximal biceps tenodesis.

Here, we are loading the button. You want to first start by cutting the loop at the end of your distal biceps tendon so you have 2 different limbs. You take a free needle and you load the button going through 1 hole and back through the other hole, with the 2 limbs facing the same direction. Once you have 1 limb of your suture loaded, you do the same with the other limb of your suture, except this time you enter through the hole that you exited with the first limb and then you exit through the hole that you first entered with the first limb of your suture. Once loaded, you should have all 4 strands from both limbs of your suture facing the same direction of the button.

Here is the proximal radius with the biceps tuberosity. If you need to remove any stump, you should do so for preparation of biceps reinsertion. You can prepare the tuberosity by gently decorticating it with a curette or rongeur. However, be careful not to compromise the integrity of the cortical wall.

Now with the forearm fully supinated and the tuberosity in plain view, we drill at a slight angle for more anatomic position and to make it easier to unload the button.

Here is our drill hole. The biceps button can easily slide down the 2 suture limbs on its way into the drill hole. Once seeded in the drill hole, apply direct pressure until you see and hear a pop of the button seeding into the intramedullary canal, as seen here. Once that happens, keep applying pressure on the handle and unscrew the back of it to remove the handle. By drilling at an angle, you should avoid deployment failure inside the intramedullary canal. However, one nice thing about using a button is if you have deployment failure, you can pull the button back out with the suture limbs and reload it onto the handle so you can try again.

Because the suture limbs slide through the button, you can pull on each limb sequentially to maximize your tension of your repair.

We then take a free needle on 1 of the suture limbs and use that to pass it through the biceps tendon substance once or twice.

Using the sliding limb as your post, we then tie 7 or 8 square knots into the repair. We then cut the limbs of the suture, leaving a small tail, and then we have our final product of our repaired distal biceps tendon. You can see its tension here when we extend the elbow and when we pronosupinate the forearm.

Immediately after surgery, the patient’s arm is immobilized in a posterior long arm splint at 90° of elbow flexion with the forearm in neutral for 2 weeks. At the 2-week postoperative mark, the patient is transitioned into a hinged elbow brace locked at 90°. From that 2-week mark up to 6 weeks, the elbow is extended within the hinged elbow brace 10-15° for 30-40 minutes 3-4 times per day. The patients keep extending 10° every 4-5 days until full extension is reached. They keep the elbow locked at 90° otherwise for sleep and for walking around. At 6 weeks postoperative, the patient discontinues the hinged elbow brace.

The literature shows these patients generally do well after distal biceps tendon repair. Here are 2 studies that show good return of motion and strength after repair.