Anatomic Medial Ulnar Collateral Ligament Reconstruction With Internal Brace Augmentation in Throwing Athletes

Abstract

Background:

Injury to the medial ulnar collateral ligament (MUCL) is a common setback experienced by many throwing athletes often requiring reconstruction with 12 to 18 months of rehabilitation. Current reconstructive techniques fail to anatomically restore the MUCL. This presentation demonstrates the “anatomic technique” for reconstruction of the MUCL supplemented by internal brace augmentation.

Indications:

Initial injuries of the MUCL can often be managed conservatively; however, many complete tears and those failing nonoperative management are frequently treated with MUCL reconstruction.

Technique Description:

After graft harvest, a 6-cm incision is created over the medial epicondyle to expose the sublime tubercle and medial epicondyle. Sutures are placed through the torn ligament which are used to formally repair the native ligament. A 4-mm socket is drilled in the MUCL origin of the medial epicondyle, and two 2-mm penetrating sockets are drilled toward the base of the 4-mm socket. The sutures in the native ligament are passed through the sockets and later tied over the bone bridge to complete the native ligament repair. A tight rope is shuttled through the medial epicondyle socket and assembled. The palmaris longus autograft and a suture tape are loaded onto the tightrope and reduced into the humeral socket. On the ulna, soft suture anchors are placed on either side of the sublime tubercle. The distal end of the graft is then sutured utilizing a FiberWire. The graft is secured to the sublime tubercle by tying down the previously placed suture anchors. The suture tapes and internal brace are loaded into a SwiveLock suture anchor, which is fixed distally along the sublime tubercle ridge creating an anatomic reconstruction. Then, the native ligament sutures and tight rope are re-tensioned and tied across the humeral bone bridge for final fixation.

Results:

In our cohort of 26 professional and amateur throwers, >90% returned to play at the same level at a mean of 9.9 months postoperatively.

Discussion/Conclusion:

Anatomic reconstruction of the MUCL with internal bracing is a viable option for MUCL injuries and may allow expedited return to sport for most athletes.

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 presentation, we will demonstrate how to perform a medial ulnar collateral ligament (MUCL) reconstruction using an anatomic technique with internal brace augmentation for throwing athletes. The rate of MUCL injuries continues to rise, and these are commonly treated with surgical repair or reconstruction. Reconstruction typically requires 12 to 18 months of postoperative rehabilitation.^2,4,5,8 A number of different surgical techniques have been developed in the past; however, most of these do not anatomically restore the native MUCL anatomy.^1,3,6,7

In recent years, we described an anatomic MUCL reconstruction technique that was designed to try to mimic the anatomy of the native ligament, and in biomechanical testing, this proved to have improved biomechanical strength compared to the docking technique.^1,7 This technique also allows for concomitant repair of the native MUCL under the graft, and a suture tape or internal brace can easily be added to improve the overall biomechanic strength. In this presentation, we will demonstrate the anatomic reconstruction of the MUCL with internal bracing and provide outcomes for both amateur and professional throwers.

Our patient is a 25-year-old right-hand-dominant professional baseball pitcher that has chronic medial elbow pain and decreased pitching velocity. This has persisted despite a comprehensive course of nonoperative treatment. Upon examination, he has full range of motion and strength. He has tenderness to palpation over the medial epicondyle and the MUCL origin with a markedly positive moving valgus stress test. His exam for the flexor/pronator and ulnar nerve were negative. The magnetic resonance imaging (MRI) demonstrates a complete proximal tear of the MUCL with significant degeneration of the ligament in the intrasubstance. The surgical plan is to repair the native MUCL and perform a reconstruction using an ipsilateral palmaris longus autograft with an anatomic technique that is augmented by an internal brace. The patient will be positioned supine with the arm out on an arm board.

A small incision is created over the proximal wrist crease. The palmaris longus is identified and sutured. It is then harvested in a standard fashion using a 5-mm tendon stripper. Great care is taken to follow the course of the palmaris longus toward the medial epicondyle. Once it is harvested, a metal ruler is then used to remove any remaining muscle fibers from the tendon so that we have a clean tendon graft.

Attention is then turned to the medial elbow where a 6-cm incision is made just over the medial epicondyle, 2 cm proximal to the medial epicondyle and 4 cm distal. The sublime tubercle is palpated, and a split in the flexor/pronator musculature is created centered over the sublime tubercle. Blunt dissection is used to carefully slide through the flexor tendon down to the MUCL. The sublime tubercle and the sublime tubercle ridge are identified. The ligament is then elevated through the proximal tear so that the joint line can be identified. It is sutured using a 0 FiberWire suture (Arthrex, Inc.) in a running Krakow fashion, and this will be used to repair the native ligament later in the case.

A 4.0-mm socket is drilled in the MUCL origin in the medial epicondyle to a depth of 15 mm using a UCL drill guide and instrumentation set. A chamfer tool is used to clean up the edges of this. A c-shaped guide is then used to drill two 2.0-mm penetrating sockets proximal to that. Shuttling sutures are then passed through these in a bidirectional fashion. Two shuttling sutures are passed through each of the smaller sockets and will be used for later graft and tight rope shuttling. One of the shuttling sutures is used to shuttle one of the sutures from the native ligament, and the other is tagged and laid aside. Two additional bidirectional shuttling sutures are passed through the remaining socket. Once again, one of these is used to shuttle the suture of the native ligament. When these two are tied down later in the case, this will complete the repair of the native ligament.

A bone-tendon-bone (BTB) tight rope without a button is then brought up to the table and taken off of the card. The long loop is passed from proximal to distal and then tagged. On the other side, the shuttling stitch and the remaining free suture are shuttled through from proximal to distal. The small shuttling stitch is tagged, and then the longer suture is pulled and passed through the previously passed loop. This creates the tight rope that will contain the graft and internal brace on the distal side. The stitch is loaded back onto the shuttling suture and shuttled back through. It is then shuttled through the tight rope. This completes the creation of the tight rope over the bone bridge. Slack is then taken out of the tight rope, and it is tensioned on both sides. Here you can see the final construct.

The graft and suture tape are then loaded onto the distal end of the tight rope, which is then reduced into the humeral socket. One of the main benefits of using the tight rope is that it allows the graft to be re-tensioned at the end of the case after it has already been fixed on the ulna; however, if the suture passing is too complex or difficult, a simple suture tape can be passed through to create a loop and then tied at this stage. Although that does not allow re-tensioning, it does make a more simple construct. At this point, the folded graft and suture tape are reduced into the socket using adjustable loop fixation that can be re-tensioned at the end of the case. Now we will turn our attention to the ulna where the proximal anchors will be placed.

Knot-tying FiberTak anchors (Arthrex, Inc.) are placed in the proximal ulna on either side of the sublime tubercle just distal to the joint line and on the anterior and posterior edges of the native ligament. The graft is marked where it intersects those sutures. A looped FiberWire is then used to run a running, locked, looped suture around both limbs of the graft and the internal brace. One suture from each of the anchors is then passed between the two limbs of the graft just proximal to our FiberLoop (Arthrex, Inc.). These will then be tied to secure the graft proximally. Excess graft is cut, and the graft and internal brace are clamped and then reduced by holding the clamp distally. The sutures are then tied to secure the anterior limb of the graft, as well as the posterior limb. Excess suture is cut.

The suture tapes from the graft and the internal brace are then loaded onto a 3.5-mm SwiveLock suture anchor (Arthrex, Inc.). Distal to the sublime tubercle and the sublime tubercle ridge, the anchor hole is drilled and double tapped. The anchor is then fixed with the elbow reduced at 45° flexion, and a varus load applied. Again, this anchor contains the two limbs of the internal brace suture tape and the two limbs of the looped FiberWire that will run in the graft.

The sutures from the native ligament are tied, and then the tight rope is re-tensioned and tied. Excess suture is cut, and the fascia is closed over the top. Suture is then passed through the native ligament and graft so that the native ligament, graft, and internal brace are all unitized. Fascia is closed in a standard fashion.

Here is an illustration to highlight the configuration of the graft. The folded end is docked into the socket on the medial epicondyle, and the suspensory loop is tied to create a closed loop construct on that side. On the ulnar side, the triangular footprint of the native MUCL is recreated using the three anchors. This relies on onlay fixation. Accordingly, the underlying bone can be prepared by utilizing cautery to gently elevate the periosteum and a curette to scrape the underlying bone so that it is suitable for healing.

Postoperatively, patients are maintained in an elbow brace at approximately 70° of flexion that is locked for 2 weeks. From weeks 2 to 6, the brace is unlocked, and range of motion is progressed as tolerated. Strengthening begins and is progressed from week 6 to 12. An interval throwing program is generally initiated around month 3, and mound throwing begins around month 5 or 6 once the athlete meets appropriate criteria. The ultimate goal for return to competitive pitching is around 9 months, but this depends on the progression through the rehabilitation and the ultimate goals of the athlete. Athletes can generally return to play once they have full motion, full strength, no pain, normal physical exam, and have completed the throwing progression.

In 26 professional and amateur throwing athletes who have undergone MUCL reconstruction with an anatomic technique, 90% were able to successfully complete the accelerated rehabilitation protocol. The median time to first throw was 3 months, and the mean time to return to play was 10 months. Eighty-five percent of these athletes were able to return to the same level of play, the same role, and were able to get back for the next competitive season. In this group, KJOC (Kerlan Jobe Orthopaedic Clinic) scores improved from 41 preoperative to 87 postoperative, and SANE (Single Assessment Numerical Evaluation) scores improved from 33 preoperatively to 96 postoperatively.

Overall, in this cohort, 92% of throwers were able to return to play at an average of 10 months after surgery. Eighty-five percent returned to the same role and the same level of play. Potential advantages of this technique include increased tendon-bone contact on both the humeral and ulnar sides and multipoint fixation to better span and recreate the native ulnar insertional footprint. It allows for a larger graft size without having to remove any additional bone. There is also the opportunity to repair the native MUCL underneath the reconstruction. There is also the ability to add an internal brace, and this construct more closely represents the native anatomy of the MUCL.

So, in conclusion, anatomic reconstruction of the MUCL with internal bracing is a viable option for MUCL injuries and may allow expedited return to sport for some athletes. However, additional long-term follow-up is certainly needed.