The Combined “Double Pulley”–Simple Knot Technique for Arthroscopic Shoulder Posterior Labral Repair and Capsular Shift

Abstract

Posterior shoulder instability is more prevalent than traditionally believed. Surgical repairs of posterior shoulder instability have overall good success rates. However, in elite overhead and throwing athletes, a low rate of return to the preinjury level of play after repair remains a challenge. The 2 goals of posterior shoulder stabilization surgery are secure fixation of the labrum to the glenoid and retensioning of the posterior capsulolabral complex. Recent studies have shown significant advantages of arthroscopic anatomic repair over open nonanatomic techniques. We report a combined double pulley–simple knot technique for arthroscopic fixation of posterior labral tears and capsular shift. The technique incorporates several advantages of this hybrid fixation method.

Unidirectional posterior shoulder instability is far less common than anterior instability. However, recent studies have suggested that in a young active population, it is more prevalent than traditionally believed, with an incidence of 24% reported for isolated posterior instability and 19% for combined posterior and anterior instability.¹

Multiple open and arthroscopic techniques have been described for reconstruction of the posterior capsulolabral complex. Recent studies have shown significant advantages of arthroscopic anatomic repair over open nonanatomic techniques.² Moreover, arthroscopic stabilization procedures using suture anchors result in fewer recurrences and revisions than anchorless repairs.³

In a young athletic population that underwent arthroscopic posterior capsulolabral repair for symptomatic posterior shoulder instability, the success rate was greater than 92%, with an over 85% rate of return to sports.4, 5 However, the results regarding return to the preinjury level of sport are much less satisfactory, with a less than 70% rate of return to the same level among all athletes and less than 60% in throwing athletes.⁶

The 2 goals of posterior shoulder stabilization surgery are secure fixation of the labrum to the glenoid and retensioning of the posterior-inferior glenohumeral ligament complex and posterior capsule.⁷ Although current techniques achieve these goals by using a series of “spot welds” holding the repaired labrum and capsule in position until biological healing occurs, this may lead to the formation of gaps between the labrum and glenoid bone in the intervals between the anchors. Moreover, these techniques result in a concentrated point load of the reconstructed labrum, ligaments, and capsule. Better reconstruction of the native anatomy and forces across these posterior structures should improve healing; this could improve the rate of return to the preinjury level of performance among high-level athletes.

We describe a combined double pulley–simple knot technique for treatment of posterior shoulder instability. The simple-knot component of this technique provides secure fixation of the labrum to the glenoid. The double pulley is used to tension the posterior capsule and ligaments in a symmetrical manner and improve the footprint of healing along the glenoid neck.

Surgical Technique

This technique was developed as a more anatomic repair of posterior labral tears of the shoulder. It combines simple vertical suture fixation of the posterior labrum with a double-pulley suture configuration for posterior capsular shift and posterior periosteal sleeve repair (Video 1, Table 1). The patient is placed in the beach-chair position using a Spider Limb Positioner (Tenet Medical, Calgary, Alberta, Canada) to hold the arm in the desired position. A 30° arthroscope (Smith & Nephew, Andover, MA) is introduced into the glenohumeral joint through a standard posterior portal. An anterior portal is established high in the rotator interval region using a spinal needle by an outside-in technique. The needle is replaced with an 8.25-mm arthroscopic shoulder cannula (Smith & Nephew).

Table 1.

Step-by-Step Combined Technique for Posterior Labral Repair and Capsular Shift

1. Position the patient in the beach-chair position.

2. Perform diagnostic arthroscopy through the posterior portal and the anterior portal (place an 8.5-mm cannula in both portals).

3. Use a spinal needle and No. 11 blade knife to place a trans-cuff portal medial to the rotator cuff cable while viewing from the posterior portal (place a 5.5-mm smooth cannula over the switching stick into the joint).

4. Use a rasp and 4.5-mm shaver to prepare the posterior glenoid neck and posterior labrum.

5. Through the posterior portal, place a Smith & Nephew Suturefix 1.9-mm double-loaded anchor at the posterior-inferior edge of the tear.

6. Use a shuttling device to retrieve 1 arm of the suture from the anchor through the posterior labrum.

7. Through the posterior portal, use an arthroscopic simple vertical knot–tying technique to fix the posterior labrum.

8. Through the posterior portal, use a shuttling device to retrieve the 2 arms of the other suture on the anchor through the posterior labrum and posterior capsule about 1 cm lateral to the labrum.

9. Through the posterior portal, place a second Smith & Nephew Suturefix 1.9-mm double-loaded anchor on the posterior glenoid rim about 1 to 1.5 cm from the first anchor.

10. Use a shuttling device to retrieve 1 arm of the suture from the anchor through the posterior labrum.

11. Through the posterior portal, use an arthroscopic simple vertical knot–tying technique to fix the posterior labrum.

12. Through the posterior portal, use a shuttling device to retrieve the 2 arms of the suture on the anchor through the posterior labrum.

13. Retrieve the 4 limbs through the posterior portal.

14. Through the posterior cannula, tie the sutures from the 2 anchors using a double-pulley technique.

Complete diagnostic arthroscopy of the glenohumeral joint is performed. Associated intra-articular pathology is documented and addressed as indicated. Then, with a probe, the posterior labral tear is confirmed (Fig 1). Once the lesion is verified, a trans–rotator cuff portal is created medial to the rotator cuff cable (musculotendinous junction) using a spinal needle as described by O'Brien et al.⁸

Fig 1.

By use of a probe through the posterior portal, the posterior labral tear is confirmed. A left (L) shoulder is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Viewing through the anterior portal, the surgeon uses a 4.5-mm shaver (Smith & Nephew) through the trans–rotator cuff portal to debride the posterior glenoid neck to bleeding bone and the edge of the posterior labrum as indicated. Through the posterior portal, a Smith & Nephew Suturefix 1.9-mm double-loaded anchor is placed at the inferior extent of the posterior labral tear on the glenoid rim (Fig 2). Three suture arms are retrieved through the anterior portal, with one suture end being left in the posterior portal. Viewing through the trans–rotator cuff portal, the surgeon uses a 45° left lasso-loop device (Arthrex, Naples, FL) (for a right shoulder) through the posterior portal to shuttle the remaining suture arm through the posterior labrum. An arthroscopic simple vertical knot–tying technique is used through the posterior portal to fix the labral tear (Fig 3). The 45° left lasso-loop device is used again through the posterior portal to penetrate the posterior capsule about 1 cm away from the labrum to shuttle the other 2 arms of the second suture on the anchor through the posterior labrum and posterior capsule (Fig 4). A second Smith & Nephew Suturefix 1.9-mm double-loaded anchor is placed on the glenoid rim about 1 to 1.5 cm proximal to the first anchor. Viewing through the trans–rotator cuff portal, the surgeon uses the 45° left lasso-loop device (for a right shoulder) through the posterior portal to shuttle the remaining suture arm through the posterior labrum. An arthroscopic simple vertical knot–tying technique is used through the posterior portal to fix the labral tear (Fig 5). The 45° left lasso-loop device is used through the posterior portal to shuttle the 2 remaining suture arms through the posterior labrum and the posterior capsule about 1 cm away from the labrum. By use of a suture manipulator, the 4 limbs of the 2 sutures are retrieved through the posterior portal (Fig 6). One suture limb for each anchor is chosen to be coupled in a double-pulley configuration (Fig 7). Once the double pulley is completed, fixation of the posterior capsule and periosteal sleeve is completed with tightening of nonsliding knots on the remaining suture limbs of each anchor (Fig 8). At the end of the procedure, the adequacy of the repair is confirmed using a probe (Fig 9). The shoulder is taken through a full range of motion to rule out tension on the repair that can lead to stiffness.

Fig 2.

A Smith & Nephew Suturefix 1.9-mm double-loaded anchor is placed at the posterior-inferior edge of the tear. The same left shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 3.

An arthroscopic simple vertical knot (arrow) is used to fix the posterior labrum. The same left shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 4.

The 2 arms of the other suture on the anchor are retrieved through the posterior labrum and posterior capsule about 1 cm lateral to the labrum. The same left shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 5.

A second Smith & Nephew Suturefix 1.9-mm double-loaded anchor is placed on the posterior glenoid rim (arrow) about 1 to 1.5 cm from the first anchor. An arthroscopic simple vertical knot–tying technique is used to fix the posterior labrum. The same left (L) shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 6.

The 2 arms of the suture on the second anchor are retrieved through the posterior labrum. The same left (L) shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 7.

One suture limb for each anchor is chosen to be coupled in a double-pulley configuration. The same left (L) shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 8.

Fixation of the posterior capsule and periosteal sleeve is completed with tightening of nonsliding knots on the remaining suture limbs of each anchor. The same left (L) shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

Fig 9.

(A) The adequacy of the labral repair is confirmed using a probe. (B) A balanced capsular plication is confirmed using a probe. The same left (L) shoulder as in Figure 1 is shown, in the beach-chair position, viewing through the trans–rotator cuff portal.

The postoperative protocol consists of neutral-rotation immobilization for 4 weeks. Early pendulum shoulder exercises and distal range-of-motion exercises involving the elbow, wrist, and hand are initiated immediately. Passive range of motion of the shoulder should be started during the first 2 weeks postoperatively, with a gradual progression of forward flexion from 90° to 150° over a period of 6 weeks. Active range of motion of the shoulder and a progressive strengthening program start at 6 weeks after the operation. Return to unrestricted activities, including vigorous sports, is permitted at 6 months postoperatively.

Discussion

Successful restoration of posterior shoulder stability is directly related to retensioning of the posterior shoulder capsuloligamentous complex and secure fixation to the glenoid.⁷ Current techniques for posterior shoulder stabilization use a series of spot welds between the labrum and posterior capsule to the glenoid, leaving gaps between the fixation points, as well as creating disproportionate tension in the posterior capsuloligamentous complex. Furthermore, these repair techniques rely on a nonanatomic small footprint area of healing along the glenoid rim.

This article presents a combined double pulley–simple knot technique for the treatment of symptomatic posterior shoulder instability that has failed nonsurgical treatment. This technique incorporates several advantages of this hybrid fixation method. It uses suture anchors for the repair, which has been shown to result in fewer failures and revisions compared with anchorless repairs.³

The simple vertical suture configuration provides a strong initial fixation and re-creates the tight anatomic fixation of the posterior labrum to the glenoid.⁹ The “double-pulley” technique has been described as providing stable fixation with a broad area of tissue compression against the native bone bed in cases of bony Bankart repair,¹⁰ rotator cuff repair,¹¹ remplissage procedure,¹² and avulsion fracture of the greater tuberosity.¹³

The double-pulley component in our technique has several advantages (Table 2): First, it provides secure fixation of the posterior capsule, ligaments, and periosteal sleeve between each suture anchor, thereby improving the footprint of healing along the glenoid neck and creating a seal that should prevent recurrent posterior paralabral cysts. Second, it enables the surgeon to easily control the amount of posterior capsular plication and evenly distributes the tension of the posterior capsule and ligaments. Furthermore, it has been shown that horizontal fixation of the periosteal labral complex better restores the native anatomy.¹⁴ The third advantage is that the horizontal configuration of the double-pulley technique minimizes the amount of suture material in direct contact with the articular cartilage.

Table 2.

Indications, Advantages, Disadvantages, Pearls, and Pitfalls of Arthroscopic Combined Technique for Posterior Labral Repair and Capsular Shift

Indications

Symptomatic posterior shoulder instability

Advantages

Stable horizontal fixation in addition to stable rigid fixation of posterior labral edge

Broad area of compression of posterior labral periosteal sleeve against native bone bed of glenoid neck

Suitable for large and complex posterior labral tears

Watertight repair of posterior labral periosteal sleeve—especially important when a paralabral cyst is present

Even tensioning of posterior capsuloligamentous complex

Simple technique that does not add steps, time, or level of complexity to currently used techniques

Technique can easily converted back to traditional repair methods if needed

Disadvantages

Failure of 1 of the 2 anchors will lead to total failure of the double-pulley fixation.

Pearls

Use a spinal needle with an outside-in technique to place the trans–rotator cuff portal medial to the supraspinatus cable to avoid damage to the tendon.

Verify that both sutures slide freely before performing the double-pulley part of the technique.

Pitfalls

When drilling the glenoid rim for the second anchor placement, be careful not to drill into the first anchor.

Our technique can be performed while the patient is in the beach-chair or lateral decubitus position. It is simple and does not add to the complexity level, cost, or surgical time of the currently used techniques. Moreover, the surgeon can easily convert back to the traditional techniques at any stage of the operation if needed.

There is no consensus regarding the use of a trans–rotator cuff portal during arthroscopic posterior shoulder stabilization surgery. The combined double pulley–simple knot technique can be performed as described or without the use of the trans–rotator cuff portal depending on surgeon preference.

A limitation of the described technique is that failure of one of the anchors will cause total failure of the double-pulley fixation and posterior capsular plication. More research on the biomechanical advantages of this technique is required, but it holds promise in trying to improve the clinical outcome and rate of return to the previous level of sport in competitive athletes with posterior shoulder instability.

Supplementary Data

Video 1

Repair of a posterior labral tear with a capsular shift using the double-pulley technique is shown in a left shoulder in the beach-chair position. The primary viewing portal is the trans–rotator cuff portal.