Repair of the Medial Ulnar Collateral Ligament of the Elbow With Internal Brace Augmentation

Abstract

Background:

The medial ulnar collateral ligament (MUCL) is the primary restraint to valgus force across the elbow during throwing. The incidence of MUCL continues to rise, and injuries are common in overhead throwing athletes often leading to elbow pain and instability. While MUCL reconstruction remains the gold standard for high-level throwing athletes with midsubstance tears, MUCL repair remains an option for select athletes and affords good functional outcomes with quicker return to sport compared with reconstruction.

Indications:

Indications for MUCL repair include acute injuries, proximal or distal avulsions, young and lower demand athletes, non-throwing athletes, or older athletes who may be nearing retirement.

Technique Description:

An incision is made over the medial elbow from the medial epicondyle to the sublime tubercle. Dissection is carried down to fascia which is split in line with its fibers. The flexor pronator muscle group is bluntly divided, and the ligament exposed. Care is taken to identify and dissect the native ligament. The avulsed portion of the ligament is secured with a 0 FiberWire suture in a running locked whipstitch fashion. The footprint of the avulsed ligament is gently debrided and prepared using a scalpel. The 0-FiberWire suture tails are then loaded onto a suture anchor preloaded with suture tape. This is then secured at the footprint of the ligament. The FiberWires are cut, and the suture tape is then pulled back over the native ligament and fixed at the other attachment site for the ligament. 0-Vicryl sutures are then used to suture the internal brace to the underlying ligament so the construct would move as a single unit.

Results:

Biomechanical testing has demonstrated that MUCL repair with internal brace augmentation has similar time-zero failure strength when compared with the original Jobe reconstruction technique while also having greater resistance to gapping. In addition, recent literature has shown that well-selected patients can have excellent functional outcomes and quicker return to sport with MUCL repair as opposed to reconstruction.

Discussion:

Medial ulnar collateral ligament repair with internal brace augmentation can be a successful treatment in the appropriately indicated athlete to allow for good functional results and quicker return to sport.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we’ll demonstrate our preferred technique for repair of the medial ulnar collateral ligament (MUCL) of the elbow with internal brace augmentation.

We’ll provide a brief background, discuss indications and contraindications, provide a case presentation, and describe patient positioning and the surgical technique. We will also provide our recommendations for post-operative management and briefly review patient outcomes.

It is well known that the MUCL of the elbow is the primary restraint to valgus force during the throwing motion.^1,8,9 The most common injury mechanism occurs through high repetitive loading during the late cocking and early acceleration phase of throwing. Patients commonly present with medial elbow pain and decreased throwing velocity, decreased control, and decreased throwing stamina.^1,9

MUCL injuries continue to rise year over year, and this is particularly true in our younger athletes. While MUCL reconstruction remains the gold standard for many high-level throwing athletes, MUCL repair has become a viable option in recent years. Recent studies have suggested good functional outcomes and quicker return to sport times compared with historical methods of reconstruction.

Although it is difficult to truly define an ideal candidate for MUCL repair, candidates may be considered if they have injuries that are relatively acute, that are purely proximal or distal avulsions, if they are younger or lower demand, or if they are a non-thrower or somebody who may be nearing retirement and needs a quicker recovery. Relative contraindications to MUCL repair include midsubstance tears, having generally poor ligament quality, or maybe a high-level pitcher who really desires to have a long future career.

Our illustrative case for this surgical technique is an 18-year-old right-hand dominant collegiate baseball pitcher. He experienced acute right medial elbow pain while throwing approximately 2 months prior. He describes pain, loss of velocity, and difficulty with control while pitching. He denied any ulnar nerve symptoms. His symptoms have persisted despite a comprehensive course of non-operative treatment of 8 weeks.

On physical examination, he had full elbow range of motion and full strength in all directions. He was exquisitely tender to palpation at the MUCL origin and had a markedly positive moving valgus stress test. This was true at the time of injury and again after 8 weeks of non-operative treatment. He had no ulnar nerve symptoms.

His magnetic resonance imaging demonstrates a complete proximal tear of the MUCL from its origin on the medial epicondyle. The ligament itself is relatively robust and of good overall quality. Accordingly, we felt that he was an appropriate candidate for MUCL repair with internal brace augmentation.

For surgery, the patient is positioned supine with the arm out on an arm board. We prep out the entire arm including the wrist, and a non-sterile tourniquet is placed high on the arm.

A 5-cm incision is created over the medial elbow distal to the medial epicondyle and anterior to the ulnar nerve. Sharp dissection is carried down to fascia, and the fascia is split in line with its fibers over the MUCL. Blunt dissection is carried out through the flexor carpi ulnaris (FCU) down to the MUCL and the sublime tubercle. It’s important to continuously palpate the location of the sublime tubercle to serve as a landmark to know where the dissection should occur and to minimize any unnecessary muscle damage.

Once the ligament is identified, the integrity is assessed. In this case, the ligament was injured proximally. A scalpel is then used to release the MUCL from its attachment site on the medial epicondyle. Care is taken to ensure that the ligament is released and mobilized in a full-thickness fashion, and this allows visualization of the joint. It is left attached at its distal attachment where it is currently intact.

Here you can see that the ligament is quite robust and of good quality. A 0-FiberWire suture is then run up and down the ligament in a running, locking, Krakow fashion. This begins proximal at the tear site, and travels down the anterior aspect of the ligament and then is brought back up on the posterior side of the ligament so that the free end of the suture winds up on the same spot where we started. Once it is sutured, our attention is turned to the medial epicondyle.

A knife is then used to prepare the bone, and the origin of the MUCL is identified. A drill bit is then used to drill a hole that will accept a 3.5-mm SwiveLock anchor. It’s important to get this hole lateral, which is closer to the trochlea, at the site of the anatomic origin. After it is drilled, it is tapped. The repair stiches from the ligament are then loaded onto the 3.5-mm SwiveLock suture anchor that has been preloaded with a suture tape. The suture tape will serve as the internal brace in this case. This is secured with the elbow in approximately 50° of flexion and a varus load applied.

After it is secured, the two suture tapes are then loaded onto a free 3.5-mm SwiveLock suture anchor. This is clamped and set aside. A relative isometric point is identified distally. This point is then marked, and the arm is taken through an arc of flexion and extension to ensure that the suture tape is tight throughout the entire arc of motion. Once this point is identified, it is then drilled. This bone can be quite tough so typically two taps are used; first a 3.5-mm tap followed by a 3.9-mm tap.

The tape is then maximally tensioned with the arm around 50° of flexion and it is fixed in place. The anchor that is loaded with the 2 strands of suture tape is then impacted into place. It is tightened with the arm in 50° of flexion and a varus load applied. The inserter is then removed, excess suture tapes are cut, and the elbow is taken through an arc of flexion and extension to ensure that full flexion can be achieved. Once this is confirmed, the entire construct of the internal brace and the repaired ligament are all sutured together using a 0-Vicryl suture in an interrupted fashion. Multiple sutures can be placed if necessary.

Afterward, the fascia is closed using a running locked stitch and the medial antebrachial cutaneous nerve is allowed to take its normal position. The patient is then placed into a rigid splint with the elbow at 70° of flexion and neutral rotation.

Postoperatively, we maintain the rigid splint for the first 2 weeks. From weeks 2 to 6, the patient is allowed range of motion as tolerated in a hinged elbow brace and can begin working on the more proximal segments of the kinetic chain. At week 6, gentle strengthening and a thrower’s 10 program begins. We then initiate the throwing progression around week 12, once the patient has achieved full range of motion of both the shoulder and the elbow and has appropriate strength. Once the patient is comfortably throwing out to 120 feet on a line, we then initiate the mound phase which is progressed as tolerated. The overall goal is to allow them to return to play around 6 to 9 months postoperative.

Multiple studies now published on clinical outcomes of MUCL repair with internal brace augmentation,^1-6,10 and a recent study by Dugas et al^3,4 reported favorable outcomes for 111 patients who had a 92% return to play rate at a mean time of 6.7 months.

In addition, Savoie et al ⁷ have demonstrated favorable outcomes in 60 patients who had a 97% return to play rate at 6 months postoperative.

Finally, O’Connell et al ⁵ reported on 40 MUCL tears treated with repair with internal brace. They demonstrated a mean postoperative Kerlan-Jobe Orthopaedic Clinic score of 93, and the vast majority were able to return to sport around 7 months postoperative.