Arthroscopic Treatment of Anterior Shoulder Instability Using Suture Anchors With Pre-Tied Knots in the Beach Chair Position

Abstract

Background:

Arthroscopic Bankart repair is routinely performed for treatment of anterior shoulder instability. Although an overall successful procedure, arthroscopic free-hand knot tying can be challenging and inconsistent, even for experienced surgeons. Knotless anchors, on the other hand, pose challenges in developing consistent good loop security prior to implantation, and, in the absence of a secure loop tissue tension on the glenoid face, might be inadequate. As an alternative, suture anchors with pre-tied knots offer the strength and security of knots without the need to perform complex and unreliable free-handed ties. Furthermore, loop security is consistent, reliable, and effective with each anchor.

Indications:

Patients with anterior labral tears and minimal bone loss are candidates for arthroscopic Bankart repair. The goal of surgery is to restore a robust tissue profile and statically keep the humeral head well-seated within the glenohumeral joint space.

Technique Description:

We demonstrate how to perform Bankart repair using suture anchors with pre-tied knots. The torn labrum is first mobilized and elevated, and suture anchors are placed along the glenoid rim from inferior to superior, treating the torn tissue as “rungs of a ladder.” The pre-tied sliding knot secures the restored labrum, along with glenohumeral ligaments and capsule, as necessary, using only a limited number of incrementally tensioned half hitch knots.

Results:

Of the 30 patients treated for anterior shoulder instability using this technique, the majority met the minimal clinically important improvement in the American Shoulder and Elbow Surgeons Shoulder Score, Western Ontario Shoulder Instability Index, and Marx activity scale by 2 years. Two patients reported experiencing subsequent minor subluxation events that improved following short courses of physical therapy, and no patients sustained subsequent frank dislocations.

Discussion/Conclusion:

Using suture anchors with pre-tied knots for arthroscopic Bankart repair allows for fast, easy, and consistently dependable reconstruction of the labrum and leads to reliable clinical outcomes.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we will demonstrate how to perform arthroscopic treatment of anterior shoulder instability using suture anchors with pre-tied knots in the beach chair position. We will also present prospective data from a case series of 30 of our patients treated for anterior shoulder instability using this technique.

The objective of this video is to demonstrate the use of suture anchors with pre-tied knots for arthroscopic Bankart repair. We will first cover some background on anterior shoulder instability, Bankart repair, and suture anchors with pre-tied knots. We will then present a case demonstrating the preoperative planning, operative technique, and postoperative management, and will finish with a look at our patients’ outcomes.

Patients who experience subluxations and dislocations of their shoulder are at risk for developing recurrent instability. When the shoulder dislocates anteriorly, the humeral head can avulse the capsulolabral tissue off the antero-inferior border of the glenoid, resulting in an anterior labral tear. Because the torn labrum is no longer robust enough to hold the humeral head in place, patients with these injuries frequently experience recurrent instability, in which case surgical restoration of the labrum is required. Patients primarily complain of the subjective feeling of instability, which makes daily activities and sports challenging or impossible.

Patients with minimal bone loss are candidates for arthroscopic Bankart repair using suture anchors with either knotted or knotless designs. There are advantages and disadvantages to both designs; knotted sutures offer good knot security but have a large profile and can be difficult and time-consuming to tie, whereas knotless sutures can be placed fast and have a low profile but are potentially not as secure in their loop-tissue interface.

Suture anchors with pre-tied sliding knots combine the advantages of knotted and knotless designs. Pre-tied knots offer the strength and security of knots without the difficulties and inconsistencies of free-hand tying. They can be placed quickly and easily and provide a robust tissue footprint despite an overall low profile. Because pre-tied knots slide and are secured by a limited number of half-hitch knots, they also provide the ability to tension tissue incrementally. Cadaveric studies have demonstrated that pre-tied knots produce more consistently reliable knots that are less likely to experience slippage than hand-tied knots. Our senior author’s pre-tied construct of choice is the DePuy Mitek Gryphon suture anchor with ProKnot technology (DePuy Synthes; West Chester, PA). This construct consists of a doubled-over strand of #1 Permacord with a proprietary pre-tied sliding knot. Their cost is negotiated by health systems and is thus equivalent to traditional designs.

We will demonstrate the use of suture anchors with pre-tied knots in a 20-year-old right-hand-dominant woman who experienced a first-time shoulder dislocation while pushing herself up out of her bed one morning. She is otherwise healthy; her only significant past medical history involves a nonoperative midshaft clavicle fracture roughly 4 years prior.

In the emergency department, x-rays demonstrated a true anterior shoulder dislocation, and her shoulder was reduced. She presented to our sports medicine clinic, and we obtained an magnetic resonance imaging (MRI) showing a torn anterior labrum and a shallow Hill-Sachs lesion. The combination of the patient’s young age and relatively little inciting trauma put her at risk for developing recurrent instability, so the decision was made to pursue surgical treatment.

The patient was placed in beach chair position, which is advantageous because it prevents the need for general anesthesia that is typically utilized in the lateral decubitus position and allows for excellent access to the anterior joint line. To determine the amount of dynamic anterior instability and thus how much capsule to shift, it is important to first perform an examination under anesthesia. Here, our patient’s shoulder subluxes anteriorly with only mild force but is otherwise stable posteriorly.

A posterior portal was used for camera insertion, and anterior and anterior lateral superior (ALS) working portals were established. Placing the working portals under direct visualization safeguards against poor portal placement that could affect repair quality. To preserve the rotator cuff, all portals were established in-line with rotator cuff fibers.

The joint was inventoried, and the labral tear was found to extend from roughly 2 to 6 o’clock. Through the anterior portal, the glenoid was debrided, and the torn labrum was sufficiently mobilized and elevated using a tissue elevator.

With pre-tied knots, it is very helpful to label the free limb of the suture before seating to make it easy to identify and prevent accidentally unloading the anchor. On the back table, slide a piece of cardboard or paper between the 2 strands and mark the top strand with a marker.

We believe that it is of utmost importance to start inferiorly and work superiorly, like climbing “rungs of a ladder.” By beginning inferiorly, one can achieve better tension of the anterior band of the inferior glenohumeral ligament (AIGHL) and shift appropriate amounts of capsule to better restore the hammock-like appearance of the anterior and posterior inferior glenohumeral ligament complex.

Here, the first anchor was placed at about the 5:30 position. Using the anterior portal, insert the drill guide and drill until bottomed out. Then mallet the suture anchor in place until bottomed out. Remove the suture card from the insertion apparatus and let it hang freely. Then, remove both the drill guide and the inserter shaft. Collect the marked free limb of the suture through the ALS portal.

Next, using a suture passer through the anterior portal (the same one as the seated limb), collect the labrum and retrieve the free limb through the anterior portal so that the labrum is surrounded by both limbs of the suture. We have found that using a suture passing device that is curved in the opposite direction of the side of extremity works best to restore labral height. For example, because we are repairing the labrum of the right shoulder, we are using a passing device with a needle that curves to the left.

Dressing the knot is very simple. Pass the free limb through the opening in the suture card in either direction, double the free limb over, pinch the 2 strands together, and pop the knot the suture card. Again, pass the free limb through the opening, double the free limb over, and pinch the knot off the card. Simply rotate your wrist and the remaining suture will fall free. Pull on the free limb to slide the knot down to the joint space. If the knot engages with the tissue too close to the joint surfaces, it can lead to glenohumeral chondrolysis. To avoid this, direct the knot away from the joint space before it engages with the labrum. If engaged too early, an arthroscopic probe can be used to loosen and re-direct the knot away from the glenohumeral joint space.

To complete the construct, cut the excess suture, separate the strands, and slide a knot pusher over the free limb. Tie 1 half hitch knot to prevent the knot from backing out while allowing for incremental tensioning forward and use the knot pusher to tension the knot appropriately. Tying an additional half-hitch knot, as done here, will lock the knot in the forward direction as well. Finally, cut the suture to leave at least 2 mm tails.

Repeat these steps for the remaining anchors as indicated by the size and degree of repair necessary. Working from inferior to superior, drill a second hole into the glenoid at the site of the second suture anchor until the drill bottoms out. The second anchor was seated here at about the 4:30 position. Hammer the anchor in place, remove the drill guide, and retrieve the free limb through the ALS portal. Use a suture grabber to pass the free limb under the labrum and retrieve it out of the anterior portal so that both limbs of the suture surround the labrum.

To dress the knot, pass the free limb through the opening in the suture card, double it over, and pinch the strands together to pop the knot out of the card. Slide the knot down into the joint space and tie 1 or 2 half hitch knots to tension appropriately while directing the knot away from the joint space. Finally, cut the suture to leave about 2 mm tails.

Here, 4 suture anchors were placed at the 5:30, 4:30, 3:30, and 2:30 positions. Each anchor was placed in about 4 minutes, and the case lasted just 45 minutes in total. In contrast, a recent systematic review demonstrated that, on average, Bankart repair with traditional knotted sutures takes over 75 minutes, underscoring the speed and efficiency of pre-tied knots. Another major advantage is the robust tissue footprint that can be achieved despite the knot’s overall low profile, as demonstrated in this collection of images from our case series.

Our senior author has been using suture anchors with pre-tied knots for over 4 years. In his experience, one of the biggest pitfalls to avoid is tensioning the knot while it is directed toward the joint space, which can lead to glenohumeral chondrolysis. If necessary, an arthroscopic probe can be used to loosen the knot before it is locked with the first half hitch so that it can be re-directed. Also, be sure to mark the free end of the suture prior to seating for easy identification and to prevent unloading the anchor. If an anchor is unloaded, a new one must be placed.

Like Bankart repair using traditional suture anchor designs, potential complications include recurrent instability, shoulder stiffness, and glenohumeral chondrolysis. The postoperative recovery period can be broken down into 3 phases. The goals of phase 1 are to protect the surgical repair and prevent a stiff shoulder. During phase 2, the patient should strive to have pain-free activities of daily living and increase shoulder range of motion while avoiding any load-bearing or overhead activities. The goals of phase 3 are to get the patient back to their previous level of activity.

The following slides outline an example rehabilitation program. Note that these guidelines should be only loosely followed as each patient will progress through exercises at different rates depending on their ability and confidence. Athletes typically do not return to noncontact sports until about 4 to 6 months after surgery and to contact sports until about 8 to 9 months.

We would now like to present outcomes from 30 of our patients treated using this technique. The average age of our cohort was 25. In all, 16 patients had frank dislocations during their inciting trauma, 18 suffered their instability event while playing sports, and most had relatively small tears requiring 2 or 3 suture anchors.

At 2-year follow-up, the vast majority have met the minimal clinically important improvement in the American Shoulder and Elbow Surgeons Shoulder Score, Western Ontario Shoulder Instability Index, and Marx activity scores. About 2/3 of patients were satisfied with the current function of their shoulder. In all, 18 patients are athletes, 11 of whom returned to sport around 5 months after surgery. Of the 7 patients who had not returned to sport, 5 were high school or college athletes who had stopped playing sports after graduating. In all, 2 patients reported experiencing a subsequent minor subluxation event after surgery, but all improved with physical therapy and did not require revision surgery. Notably, none of our patients treated with this technique have experienced subsequent frank dislocations.

In summary, arthroscopic Bankart repair is a successful procedure for treatment of anterior shoulder instability. Pre-tied knots avoid many of the difficulties of hand-tied knots and allow for fast and consistently reliable reconstruction of the labrum with excellent loop and knot security despite their overall small knot profile.

Here are some relevant references for further reading.

Thank you for your attention.