Tension Control UCL Reconstruction With Internal Brace Augmentation

Abstract

Background:

Ulnar collateral ligament (UCL) rupture is a common injury, particularly in throwing athletes. It occurs either in the acute setting or due to repetitive microtrauma. UCL reconstruction has been a successful treatment with proper patient selection. A number of different surgical techniques have been described in the literature. We developed a novel surgical technique using internal brace augmentation to address the 2 most common causes of failure: suture failure and bone tunnel fracture.

Indications:

To provide information about this novel UCL reconstruction technique.

Technique Description:

The palmaris longus graft is harvested and prepared to be used as the autograft. A 5-cm curved incision is made over the medial epicondyle of the humerus. The UCL reconstruction is then performed using the double suspensory reconstruction technique followed by an internal brace augmentation.

Results:

Excellent clinical outcomes and high return to sports rates have been reported after UCL reconstruction. In this novel technique, the addition of the internal brace provides secondary interference fixation of the graft on the humeral side along with the additional support the brace itself provides.

Discussion/Conclusion:

Using internal brace augmentation increases the stability of the UCL reconstruction while preventing suture failure and bone tunnel fracture.

Graphical Abstract.

This is a visual representation of the abstract.

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DOI: 10.1177/26350254211056665.M1

Video Transcript

We are presenting a novel technique for tension control ulnar collateral ligament (UCL) reconstruction with internal brace augmentation.

We have no disclosures.

The incidences of UCL injury and reconstruction have been rising steadily over the past decade. There is a high prevalence of UCL reconstruction in the professional ranks, with approximately 1 in 4 pitchers having undergone reconstruction. Most concerning is that the rates of UCL reconstruction are increasing rapidly in the adolescent population.

Currently, the most widely used techniques are the docking technique with palmaris longus autograft and the modified Jobe technique, with either palmaris longus or gracilis autograft.

Most common modes of failure are suture pullout or knot failure, midsubstance rupture, and bone tunnel fracture. Ulnar neuropraxia and injury to the medial antebrachial cutaneous nerve are the most common complications, with neuropraxia being more common after transposition.

Biomechanical studies have shown suspensory fixation to have comparable biomechanical properties with the docking technique. Also, single tunnel fixation has advantages, such as minimizing risk of fracture, less soft tissue stripping, and preserving bone stock for a possible revision surgery.

A biomechanical study showed augmenting UCL repair with an internal brace replicated the time-zero failure strength of traditional graft reconstruction and was more resistant to gapping at low cyclic loads.

Patients present with elbow pain, most notably in the late-cocking phase of the throwing motion. This is often accompanied by a decrease in throwing velocity and accuracy.

Evaluation consists of a physical examination, radiography, and magnetic resonance imaging (MRI) or MR arthrogram imaging.

Indications are an acute avulsion or midsubstance UCL rupture in an overhead athlete confirmed with advanced imaging. Relative indications are high-grade ulnar-sided partial tears or partial tears that have failed an attempt at conservative treatment.

The patient is positioned supine with operative extremity on an arm board and a tourniquet placed over the proximal humerus.

The palmaris tendon is digitally palpated at the distal wrist crease, and a 1-cm horizontal skin incision is used. The palmaris tendon is identified, whipstitched with 3-0 Vicryl suture (Ethicon, Inc.; Cincinnati, OH), and released from its insertion on the palmar fascia. A closed-end tendon stripper is then used to harvest the tendon in a typical fashion. The graft is then extracted from the harvest site and the skin incision is then closed with a 3-0 Monocryl suture (Ethicon, Inc.; Cincinnati, OH).

The tendon is then moved to a back table, doubled over, and the folded end is whipstitched with a #2 FiberLoop suture (Arthrex; Naples, FL) with the 2 free ends of suture exiting the most distal end of the graft. The graft measuring device is used to measure the size of the doubled overgraft, which in this case is 4.0 mm.

The medial approach to the elbow is carried out using an incision centered over the medial epicondyle. The incision is marked 2 cm proximal and 3 cm distal to the medial epicondyle. The medial antebrachial cutaneous nerve is identified at the distal end of the incision, and care is taken to avoid injuring this nerve. Next, the flexor pronator mass is split using the interval between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS), typically bisecting the palpable sublime tubercle. After the fascia is incised, the FCU-FDS interval is easiest to find proximally and is split working from proximal to distal using blunt dissection. The sublime tubercle and medial ulnar collateral ligament (MUCL) ridge are identified. A key elevator is then used to strip soft tissue and gain exposure. The MUCL is identified and inspected for pathology.

Attention is first turned to the UCL insertion site on the sublime tubercle on the lateral aspect of the ulna. Bone is subperiosteally exposed 5.0 mm anterior and 5.0 mm posterior to the apex of the sublime tubercle, which is typically 7.0 to 10.0 mm distal to the ulno-humeral joint line.

After sufficient exposure is obtained allowing visualization of a point just distal to the center of the sublime tubercle, a 3.7-mm guide pin is drilled bicortically through the proximal ulna. The trajectory of the guide pin should be 30° distal in the coronal plane of the ulna and 60° posterior in the transverse plane of the ulna, as described by Hooper et al. ¹

Next, a 4.5-mm cannulated drill is used to overream the anterior cortex to allow the graft to be pulled subcortically during fixation. It is recommended that the drill size be 0.5 to 1.0 mm larger than the diameter of the graft—in our case, we drilled a 4.5-mm tunnel for a 4.0-mm graft. Next, a 3.2 mm × 11 mm Pec Button (Arthrex; Naples, FL), preloaded with Fibertape suture (Arthrex; Naples, FL), is loaded with the previously passed palmaris longus sutures and delivered into the ulnar tunnel bicortically and deployed on the outer cortex. Next, using a tension-slide technique, the graft is shuttled into the anterior cortical aperture without completely seating it within the intermedullary canal. Final tensioning will occur after humeral fixation.

Next, attention is turned to the medial epicondyle. Using a stop-drill guide with a preset depth of 15.0 mm, a blind tunnel is created starting on the underside of the medial epicondyle aiming at the intermuscular septum. Care is taken to place this tunnel in the “crotch” of the epicondyle as far toward the midline as possible to create a sufficient bone bridge.

The 2 free ends of the previously set graft are pulled taught superficial to the epicondyle, and the proximal and distal extents of the humeral tunnel are marked on the superimposed graft limb to illustrate the portion of tendon that will sit in the tunnel. A whipstitch is placed between the marks of the graft ends which links the 2 free ends. Any excess graft proximal to the whipstitched area is removed.

Next, the guide is removed and a 2.6-mm guide pin is placed through the previously drilled tunnel aiming slightly anterior to the intermuscular septum and delivered through the proximal cortex. Next, a 2.6-mm FiberTak button (Arthrex; Naples, FL) is delivered through this tunnel and set on the outer cortex under direct visualization.

The 2 suture ends are subsequently shuttled into the FiberTak button. While shuttling each suture, it is important to keep gentle tension on both limbs of the non-shuttling suture to keep the FiberTak button engaged. Next, the graft is docked into the humeral socket using a tension-slide technique until the graft is fully seated.

Next, one limb of the suture is passed through the graft and tied to the other free end, locking the graft into position in the humeral socket. At this time, the arm is placed in 15° to 20° of flexion, and a slight varus force is applied to the elbow and graft tension is assessed. Attention is turned to the distal end of the graft on the ulna where final tensioning is performed, seating the distal end of the graft deeper into the ulnar canal. Once optimal tension is achieved, this is locked into place in a similar fashion to the humeral side—passing one limb of suture through the graft and tying it to the free end to lock the tension. The reconstructed ligament is sewn into the native ligament using 0 Ti-Cron sutures (Medtronic; Minneapolis, MN) in a figure of 8 fashion.

Next, the previously docked Fibertape in the ulnar tunnel is loaded into a 3.5 mm × 13.5 mm PEEK SwiveLock anchor (Arthrex; Naples, FL) and delivered into the humeral socket over the graft via the previously described internal brace technique completing the double suspensory fixation with internal brace augmentation.

Once the reconstruction is complete, a valgus force is applied to check the stability of the construct. Flexion and extension range of motion (ROM) of the elbow are also evaluated. Notice that the graft stays isometric through flexion and extension, while the internal brace is slightly lax to provide extra stability without capturing the joint or causing stress shielding.

We feel that this novel UCL reconstruction technique addresses the 2 most common causes of failure, which are suture failure and bone tunnel fracture with utilization of single-point fixation and elimination of the necessity to tie suture across the humeral bone tunnel. We also feel the addition of the internal brace provides secondary interference fixation of the graft on the humeral side, along with the additional support the brace itself provides. Our initial biomechanical evaluation supports this idea, and we are currently working on a biomechanical comparison study to validate the concept.

After surgery, passive ROM exercises start at the second week. Active ROM begins in the third week. The brace is usually discontinued at the fifth week, and the thrower’s program starts around week 7 and then is gradually progressed until week 32. Return to sports is allowed after successfully completing phase 4, which is usually around 8 to 12 months.

Most common complications include suture failure, midsubstance rupture, and bone tunnel fracture. Ulnar neuropraxia and injury to medial antebrachial cutaneous nerve are other complications.

Regarding outcomes, the number of revision UCL reconstructions has been steadily increasing in the last 4 decades.

A recent systematic review on over 1100 baseball players reported 95% return to play rate, with 85% returning to preinjury level. Professional baseball players had even higher return to play rate. At a mean of 69 months, the revision rate was reported as 6%.

Another systematic review on Major League Baseball players reported 80% to 97% return to play rates after primary UCL reconstruction in pitchers, with a mean return to play period of 12 months. Return to the same level of play was longer, and between 67% and 87% returned to the same level. All studies included in this systematic review reported a decrease in pitching workloads after UCL reconstruction, and return to play rates were significantly lower in catchers.

In a study by Dugas et al of 111 high school/college athletes who underwent a UCL repair with a FiberTape augmentation, return to play rate was 92% at an average time of 6.7 months.

These are our references.