Instability

INTRODUCTION

Instability of the shoulder is a vast topic with classification schemes that have focused on various elements such as etiology (traumatic versus atraumatic), direction of instability (anterior, posterior, multidirectional), bone loss (significant versus nonsignificant bone loss), and psychological factors (volitional versus nonvolitional). For purposes of the present discussion, we will subdivide our instability categories into:

1. Anterior instability (with and without bone loss)

2. Posterior instability (with and without bone loss)

3. Multidirectional instability (traumatic and atraumatic)

The first general conundrum that the surgeon faces when dealing with instability is how to determine the direction of instability. Although the direction of instability may be obvious in some cases, particularly when the patient is initially seen with an unreduced dislocation in the emergency department, in other cases, the direction of instability remains obscure. This is particularly true in patients who have only had recurrent subluxations without a true dislocation.

On physical examination, we utilize a modification of the load and shift test that we have found to be quite useful in determining the direction of instability. In performing this test with the patient in a sitting position, the examiner places the middle finger over the coracoid tip once he or she is sure that the shoulder is in a reduced position. Then, he or she applies an anteriorly directed force followed by a posteriorly directed force, all the while palpating the coracoid tip with the middle finger in order to estimate the anterior and posterior excursion of the humeral head in relation to a fixed point (the coracoid tip) (Fig. 3-1). This same maneuver is repeated with the patient in the lateral decubitus position, with the examiner performing this same modified load-and-shift maneuver with the arm in varying degrees of abduction (0°, 45°, 90°) while the examiner palpates the coracoid tip as a reference point to determine excursion of the humeral head (Fig. 3-2). With the arm in 0° of abduction, anterior stability is provided mainly by the superior glenohumeral ligament (SGHL), so excessive anterior excursion at 0° indicates SGHL injury or insufficiency. Similarly, a positive anterior load-and-shift maneuver at 45° abduction indicates damage or insufficiency of the middle glenohumeral ligament (MGHL), and a positive test at 90° abduction suggests injury to the inferior glenohumeral ligament (IGHL). It is important to understand that the physical examination is useful in providing an index of suspicion for the direction of instability, but the true direction and extent of the instability is often not evident until arthroscopic examination of the joint is performed.

The next general conundrum in instability surgery is whether or not to do arthroscopy in each instability patient. For example, a patient may have documented anterior instability (e.g., from x-rays in the emergency room) along with significant glenoid bone loss (>25% loss of the inferior glenoid diameter confirmed by 3D CT scan images). In such a patient, the surgeon may have already decided that he or she is going to do an open Latarjet reconstruction, so is there a need to do an arthroscopic evaluation as well? In our experience, the answer is a resounding “yes!” We always do an arthroscopic evaluation of every surgically treated unstable shoulder because we have
found a relatively high incidence of additional pathology that would have gone undetected and untreated without arthroscopic inspection.¹ Unexpected concomitant lesions that we have discovered and repaired include SLAP lesions, rotator cuff tears, posterior Bankart lesions, and posterior HAGL (humeral avulsion of the glenohumeral ligaments) lesions. If we had gone straight to an open Latarjet, without addressing this other significant pathology, we believe that these patients likely would have remained symptomatic from their unaddressed lesions. Our general philosophy is that the surgeon should treat all pathologic elements when the patient is under anesthesia, and the only way to be sure that all the pathology has been discovered is to do a diagnostic arthroscopy.

FIGURE 3-1 Load-and-shift test with the patient sitting. The examiner places his middle finger over the patient’s coracoid tip to serve as a reference point for translation of the humeral head as he applies first an anteriorly directed force, followed by a posteriorly directed force. If the test is positive with an anteriorly directed force in the sitting position, it suggests injury to the superior glenohumeral ligament (SGHL).

FIGURE 3-2 Load-and-shift test with the patient in the lateral decubitus position. A: A positive anterior load-and-shift test with the arm in 0° abduction signifies injury to the superior glenohumeral ligament (SGHL). B: A positive test at 45° abduction suggests damage to the middle glenohumeral ligament (MGHL).

Another general conundrum is whether to do arthroscopic instability surgery in the beach-chair position or the lateral decubitus position. The senior author (S.S.B.) spent the first 5 years of his “shoulder arthroscopy career” performing shoulder arthroscopies in the beach-chair position. After 5 years, he switched to the lateral decubitus position and immediately noticed two things:

1. Visualization for posterior instability repair was much better in the lateral decubitus position.

2. Access to the anteroinferior, inferior, and posteroinferior labrum was much easier in the lateral decubitus position.

Therefore, we strongly recommend the lateral decubitus position for all arthroscopic instability surgeries.

ANTERIOR INSTABILITY

Arthroscopic versus Open

Some authors have recommended open repair for contact athletes, citing unacceptable recurrence rates if arthroscopic repairs are performed;² however, that has not been our experience. We have found that the critical factor in predicting recurrence is to determine whether or not the athlete has significant bone loss. If our criteria for significant bone loss
are adhered to, we have not observed an increased recurrence rate in contact athletes treated arthroscopically.³,⁴ We believe that the critical factor for recurrence is recognizing significant bone loss and treating it appropriately.

FIGURE 3-2 (Continued) C: A positive test at 90° abduction indicates that the inferior glenohumeral ligament (IGHL) has been damaged.

FIGURE 3-3 Glenoid bone loss can be quantified with a three-dimensional CT of the (A) normal and (B) affected shoulders. The percentage of glenoid bone loss can be easily calculated on the en face view by comparing the inferior glenoid diameter of the normal side to that of the affected side.

LATARJET

Video 3-1 Significant Bone Loss: When Is Latarjet Necessary?

On the glenoid side, we consider that a patient has significant bone loss if he or she has lost ≥25% of the inferior glenoid diameter. This can be determined from 3D CT scans, comparing the diameters of the injured and normal glenoids (Fig. 3-3). In utilizing this modality, one must be cognizant that this method underestimated the percentage of bone loss in 8% of patients.⁵ Therefore, we continue to prefer direct arthroscopic measurement of glenoid bone loss based on the location of the glenoid bare spot (Fig. 3-4).

In terms of glenoid bone loss, our indication for a Latarjet reconstruction with coracoid bone graft is anterior instability associated with a glenoid bone loss of ≥25% of the inferior glenoid diameter. We have found that whenever we do a Latarjet reconstruction, the Hill-Sachs lesion does not need to be separately addressed. That is, after Latarjet, the coracoid bone graft and the sling effect of the conjoined tendon will always prevent the Hill-Sachs lesion from engaging, no matter how large the Hill-Sachs might be.

FIGURE 3-4 Left shoulder, anterosuperolateral viewing portal. Measuring glenoid bone loss. A: A calibrated probe introduced from a posterior portal marks the distance from the glenoid bare spot to the posterior rim. In this case, the distance is ˜12 mm. B: The probe is used to measure the distance from the anterior glenoid rim to the glenoid bare spot. In this case, the distance is 6 mm. Thus, there is 6 mm of bone loss anteriorly or 25% loss of the inferior glenoid diameter. G, glenoid; H, humeral head.

Surgical Technique of Congruent-Arc Latarjet Reconstruction

We call our surgical technique the congruent-arc technique because we place the coracoid graft in an orientation such that the arc of its inferior surface is a congruent extension to the glenoid articular arc. This requires that we rotate the coracoid graft 90° about its long axis prior to fixation to the anterior glenoid neck.

Video 3-2 We always perform diagnostic arthroscopy just prior to the Latarjet in order to accurately measure the amount of glenoid bone loss, to assess the Hill-Sachs lesion, and also to evaluate the joint for additional pathology, particularly SLAP lesions. We have found a 64% incidence of SLAP lesions in our patients who are undergoing Latarjet reconstruction.¹ In these cases, we perform an arthroscopic SLAP repair with the patient in the lateral decubitus position. Then, we turn the patient supine and adjust the table to a modified beachchair position, then re-prep and redrape for the open Latarjet.

Coracoid Osteotomy

In performing the congruent-arc Latarjet, a standard deltopectoral incision is used. The cephalic vein is preserved and retracted laterally with the deltoid muscle. The coracoid is exposed from its tip to the insertion of the coracoclavicular ligaments at the base of the coracoid. The coracoacromial ligament is sharply dissected from the lateral aspect of the coracoid, and the pectoralis minor tendon insertion on the medial side of the coracoid is also sharply dissected from the bone (Fig. 3-5). The medial surface of the coracoid, from which the pectoralis minor is detached, is the surface that will later be in contact with the anterior glenoid neck when the graft is secured by screws.

For the coracoid osteotomy, two options are available. Option 1 involves the use of an osteotome to create the osteotomy (Fig. 3-6A). We believe that an osteotome should be used only in thin patients. In a muscular patient with a large deltoid and pectoralis major, the bulk of these
muscles may prevent a proper angle of approach anterior to the glenoid, resulting in the possibility of intra-articular glenoid fracture. Option 2, for muscular patients, involves the use of an angled sawblade to create the osteotomy (Fig. 3-6B). Neurovascular structures are protected by retractors medial and inferior to the sawblade. With either technique, the osteotomy is made just anterior to the coracoclavicular ligaments in order to obtain as much length to the coracoid graft as possible. A graft measuring 2.5 to 3.0 cm in length is ideal, though in small patients a graft of 2.0 cm is adequate for fixation with two screws.

FIGURE 3-5 In preparation for coracoid osteotomy, the pectoralis minor tendon is sharply dissected off the medial edge of the coracoid.

FIGURE 3-6 Coracoid osteotomy may be performed with (A) an osteotome or (B) an angled sawblade. C, coracoid.

The conjoined tendon is left attached to the coracoid graft to maintain vascularity of the graft and to augment stability of the glenohumeral joint by providing a sling effect upon completion of the procedure. After mobilization of the coracoid and conjoined tendon, the musculocutaneous nerve is protected by retracting the coracoid medially, thereby preventing any stretch injury to the nerve.

Glenohumeral Joint Exposure

Once the coracoid has been osteotomized, there is a clear view of the anterior shoulder. The upper half of the subscapularis tendon is detached distally and reflected medially (Fig. 3-7). The insertion of the lower half of the subscapularis is preserved. After detachment of the upper subscapularis tendon, the plane between lower subscapularis tendon and anterior joint capsule is developed.

Alternatively, the glenoid may be exposed by using a subscapularis split approach. A deep Gelpi retractor is used to spread the split in the muscle. The subscapularis split is made through the muscular fibers at the junction of the superior and middle thirds of the muscle. The capsule is bluntly dissected from the subscapularis, and then, the capsular incision is made. We prefer not to use the subscapularis-splitting approach because visualization can be quite limited, and the position of the split severely limits the surgeon’s ability to change the position of the graft on the glenoid if needed. Instead, we detach the upper half of the subscapularis and then develop the plane between the lower subscapularis and capsule.

The capsular incision is begun 1 cm medial to the rim of the glenoid by subperiosteal sharp dissection to preserve enough capsular length for later reattachment (Fig. 3-8). The anterior glenoid neck is prepared as the recipient bed for the coracoid bone graft by means of a curette or a burr, being careful to preserve as much native glenoid bone as possible. “Dusting” of the anterior glenoid neck to a bleeding surface is performed with a high-speed burr without actually removing the bone.

Alternatively, in our preferred technique for bone bed preparation, a 70° angled sawblade can be used to create a completely flat surface on the anterior glenoid neck that will match the flat surface of the coracoid cut, maximizing the contact area and thereby enhancing the chances of bone union.

Coracoid Preparation

While stabilizing the coracoid with a Kocher grasper, use an oscillating saw to remove a thin sliver of the bone from the medial coracoid surface where the pectoralis minor had been inserted. This is the surface that will be in contact with the anterior glenoid neck (Fig. 3-9).

FIGURE 3-7 Management of the subscapularis tendon. Detach the superior half of the tendon and then develop a plane between the inferior half of the subscapularis and the capsule.

FIGURE 3-8 A: Outline of capsulotomy. B: Dissect the capsule 1 cm medial to the glenoid rim before detaching it from the glenoid neck to preserve as much capsular length as possible for later reattachment.

FIGURE 3-9 Coracoid graft preparation. A: The coracoid is grasped with an instrument. B: A straight sawblade is used to remove a thin sliver of bone from the medial surface. C: The medial surface has been cut and will be secured to the glenoid rim. C, coracoid graft.

FIGURE 3-10 Coracoid Drill Guide. A: The Coracoid Drill Guide (Arthrex, Inc., Naples, FL) has slots for drilling the coracoid in preparation for Latarjet. B: The elongated slots are placed on the medial surface of the coracoid graft (the side that will rest against the glenoid). The guide facilitates placement of two 4-mm parallel drill holes. C, coracoid graft.

Grasp the coracoid graft with the grasping Coracoid Drill Guide (Arthrex, Inc., Naples, FL) (Fig. 3-10). Position the guide on the graft so that the elongated clearance slots are on the freshened surface of the coracoid that will eventually be in contact with the glenoid.

The Coracoid Drill Guide allows the surgeon to drill two parallel 4-mm holes through the graft. Care is taken to ensure that the holes are centered on the graft and are perpendicular to the prepared bone surface.

Positioning the Parallel Drill Guide on the Graft

Prior to the development of the Glenoid Bone Loss Set (Arthrex, Inc., Naples, FL), the coracoid graft had to manually be positioned on the glenoid in a freehand manner. This was technically very difficult and was not easily reproducible. The Parallel Drill Guide (Arthrex, Inc., Naples, FL) has greatly simplified this part of the procedure and has also made it very reproducible.

The pegs on the Parallel Drill Guide mate with the predrilled holes on the coracoid graft (i.e., those that were created with the Coracoid Drill Guide) to allow for easy control and positioning of the coracoid graft onto the glenoid (Fig. 3-10).

FIGURE 3-11 The Parallel Drill Guide (Arthrex, Inc., Naples, FL). A: Pegs on the guide mate with the predrilled holes in the coracoid graft. Different offsets are available to accommodate grafts of varying thickness. A 6-mm offset guide is pictured. B: An optimal fit occurs when the overhanging fin is flush with or slightly above the coracoid graft. C, coracoid graft.

Three offset sizes are available (4, 6, and 8 mm) to adapt to various graft diameters. Some additional shaping of the graft with a rongeur or a power burr may be required to obtain the best possible fit of the guide against the graft. An optimal fit occurs when the coracoid is slightly below the overhanging offset fin once the pegs are fully engaged (Fig. 3-11).

Positioning the Coracoid Graft on the Glenoid and Securing the Graft

The glenoid is optimally exposed by placing a Fukuda retractor to lever the humeral head posteriorly and by placing a two-pronged Hohmann retractor medially to retract the medial soft tissues.

Proper position of the coracoid bone graft relative to the glenoid is critical. The graft must be placed so that it serves as an extension of the articular arc of the
glenoid (Fig. 3-12). The Parallel Drill Guide is invaluable in placing the graft flush with the articular surface of the glenoid so that it is neither too far medial nor too far lateral (Fig. 3-13). It is important to be sure that the guide is angled slightly medially, toward the face of the glenoid, to achieve the proper screw insertion angle and to avoid any potential screw penetration into the articular cartilage.

FIGURE 3-12 Correct placement of the coracoid bone graft occurs when the graft is flush with the glenoid surface so that the arc of the glenoid is effectively extended. The Parallel Drill Guide (Arthrex, Inc., Naples, FL) facilitates proper placement of the graft. C, coracoid graft; G, glenoid.

Use a pin driver to advance the shorter (6 inches) of the two guide wires directly through the lower hole of the guide and graft and then into the glenoid neck. The guide wires are not terminally threaded to allow for better feel when the posterior glenoid cortex is penetrated. Next, advance the longer (7-inch) guide wire through the second guide cannulation (Fig. 3-14A).

Next, remove the Parallel Drill Guide. Hold the graft firmly against the glenoid with an instrument (as the pegs may be tightly wedged into the coracoid drill holes) while the Parallel Drill Guide is withdrawn, leaving both guide wires in place (Fig. 3-14B). Although the 3.75-mm, fully threaded, cannulated titanium screws are self-drilling and self-tapping, it is recommended to use the 2.75-mm cannulated drill to penetrate only the near cortex of the native glenoid prior to screw insertion. Due to the potential proximity of the screws to the suprascapular nerve posteriorly, it is advisable to rely on the self-drilling and self-tapping nature of the screws to penetrate the posterior glenoid cortex.

FIGURE 3-13 Incorrect placement of coracoid bone graft. A: The graft must not be placed so that it protrudes lateral to the joint surface and acts as a bone block. Such placement produces a high incidence of late osteoarthritis. B: Conversely, it is important also to avoid medial placement of the graft because this can predispose to recurrent dislocation or subluxation.

The screw length depth gauge can then be used to help determine the proper screw length. Screw length is read directly from the back end of the shorter 6-inch guide wire and from the laser line of the longer 7-inch guide wire. We have found that the most common screw lengths are 34 mm for the more inferiorly positioned screw and 36 mm for the superior screw.

Each screw is inserted over its guide wire using a cannulated hex driver. One must be careful not to overtighten the screws as this may crack or damage the graft. Once the screws are almost fully seated, the surgeon double checks the position of the coracoid graft. If the position is satisfactory, the guide pins are removed and the screws are advanced to their fully seated position (Fig. 3-14C). Intraoperative AP and axillary x-rays are taken to confirm satisfactory position of the screws and graft.

At this point, the surgeon assesses the stability of the Latarjet construct. One of the most amazing things about this construct is that, with the arm in abduction and external rotation and with a manually applied anteriorly directed force, the shoulder cannot be dislocated, even though the capsule has not yet been repaired.

Capsular Reattachment

Place 3 BioComposite SutureTak anchors (Arthrex, Inc., Naples, FL) into the native glenoid above, between, and below the cannulated screws to repair the capsule. This makes the graft an extra-articular structure and prevents its articulation directly against the humeral head, eliminating
any abrasive potential of the graft against the articular cartilage of the humerus (Fig. 3-15).

FIGURE 3-14 Securing the coracoid bone graft. A: Guide wires are inserted through the Parallel Drill Guide (Arthrex, Inc., Naples, FL) to temporarily hold the graft in place. B: The drill guide is removed, and the appropriate screw length can be measured. C: Final appearance of secured graft after placement of two cannulated 3.75-mm screws. The graft is flush with the glenoid articular surface and extends the native glenoid arc. C, coracoid graft; G, glenoid.

Subscapularis Repair

If a subscapularis split has been used, the upper and lower subscapularis muscle segments will reapproximate themselves once the retractors have been removed, and no sutures are necessary. When the upper subscapularis has been detached and retracted medially during the exposure, it is usually repaired back to its stump with #2 FiberWire suture (Arthrex, Inc., Naples, FL). If the tendon stump is of poor quality, then BioComposite CorkScrew FT suture anchors (Arthrex, Inc., Naples, FL) are used.

FIGURE 3-15 Suture anchors are placed at the interface of the graft and the native glenoid arc and used to repair the anterior capsule so that the coracoid graft remains extra-articular.

It is not necessary to reattach the pectoralis minor to the residual coracoid base or adjacent soft tissues because it does not retract. We have not observed any residual symptoms or cosmetic deformity relative to the unrepaired pectoralis minor.

After subscapularis repair, a standard skin closure is performed.

Optimizing the Chances of Bone Graft Union

The key to obtaining union between the coracoid graft and the anterior glenoid is to have two large flat surfaces that are in intimate contact throughout their surfaces. We believe that the common practice of using a burr to prepare the bone surface, particularly the anterior glenoid neck surface, leaves an uneven interface that may not have good contact with the matching surface of the graft. Therefore, we use a saw to create these surfaces to ensure that they are perfectly flat.

For the coracoid graft, we have already used a straight sawblade to remove a “wafer” of the bone from the medial side of the graft (i.e., on the side where the pectoralis minor had inserted) (Fig. 3-9B).

For the glenoid side, we use a 70° angled sawblade to create a flat recipient surface on the anterior glenoid neck (Fig. 3-16A). We believe that it is important to match these two flat surfaces exactly, and the 70° sawblade gives the perfect orientation for a flush fit of the two bone surfaces (Fig. 3-16B-E).

FIGURE 3-16 Schematic showing the use of the 70° angled sawblade to prepare a flat recipient surface on the anterior glenoid neck. A: A 70° angled sawblade. B: The plane of the eroded anterior glenoid is not optimal to receive the coracoid graft at an angle that will produce a smooth articular arc between the glenoid concavity and the concavity of the graft. C: The 70° angle of the sawblade allows the surgeon to approach the anterior glenoid at a comfortable working angle to make a flat cut that is approximately in line with the axis of the scapula. D: Flat saw-cut has been completed on the anterior glenoid neck. E: Fixation of the coracoid to the glenoid neck is optimized by the perfect orientation of the two flat saw-cuts.

Postoperative Rehabilitation

The patient uses a sling for 6 weeks, with external rotation restricted to 0°. After 6 weeks, the sling is discontinued, and overhead motion is encouraged. Gentle external rotation stretching is begun at 6 weeks postoperative, with the goal that at 3 months postoperative,
external rotation on the operated shoulder will be half that on the opposite shoulder. At 3 months postoperative, the patient begins strengthening with TheraBands. At 6 months, he or she progresses to weight lifting in the gym if the graft remains in good position and shows early signs of consolidation. Contact sports or heavy labor are generally allowed when the bone graft appears radiographically healed, which is usually 9 to 12 months postoperative.

LATARJET CONUNDRA

History:

A 20-year-old college soccer player fell playing soccer 2 years ago and dislocated his right shoulder. It was reduced 2 hours later in the emergency room. Since that time, he has had four more dislocations and hundreds of subluxations. It now subluxes in his sleep.

Physical Exam:

Full range of motion, but guards with overhead motion
Normal strength
Apprehension with combined abduction and external rotation

Imaging:

X-rays show an anterior bony Bankart lesion (Fig. 3-17).
3D CT scan shows 30% glenoid bone loss with step-off and partial resorption of anterior fragment (Fig. 3-18).

Arthroscopic Findings:

Arthroscopic measurements with a calibrated probe confirmed 30% glenoid bone loss with an obvious “inverted pear” configuration of the glenoid (Fig. 3-19). The bone fragment was atrophic and not united to the glenoid.
There was a moderate-sized Hill-Sachs lesion. The Hill-Sachs engaged the anterior glenoid rim in 45° of abduction plus 30° of external rotation (Fig. 3-20).
There were no additional lesions that needed to be addressed arthroscopically.
Based on bone loss criteria (>25% glenoid bone loss), we performed an open Latarjet reconstruction.

FIGURE 3-17 Axillary x-ray shows obvious bone deficiency of the anterior glenoid.

FIGURE 3-18 3D CT en face projection of the glenoid shows an atrophic and partially resorbed bone fragment of the anterior glenoid that is medially displaced. The glenoid bone defect measures 30% of the inferior glenoid diameter.

FIGURE 3-19 Right shoulder, anterosuperolateral viewing portal. The glenoid has an “inverted pear” configuration. The anterior glenoid bone fragment is medially displaced. G, glenoid; H, humeral head.

Pearls, Pitfalls, and Decision-making:

We always perform arthroscopy prior to doing an open Latarjet for two reasons:

1. To confirm the percentage bone loss by direct measurement

2. To arthroscopically address any additional pathology (e.g., SLAP repair, posterior Bankart repair, posterior HAGL repair)
If glenoid bone loss is >25%, we perform Latarjet.
If glenoid bone loss is <25%, we consider arthroscopic Bankart repair ± arthroscopic remplissage (remplissage is added if direct measurements and calculations reveal that the Hill-Sachs lesion is “off-track”).

FIGURE 3-20 Right shoulder, anterosuperolateral viewing portal. The Hill-Sachs lesion is “perched” at the anterior margin of the inverted pear glenoid. G, glenoid; HSL, Hill-Sachs lesion.

History:

An 18-year-old male soccer player who has just completed his senior season in high school and plans to play college soccer.
In the past 2 years, he has sustained three anterior dislocations, each requiring closed reduction. Each time, the shoulder was “out” for ˜2 hours before the closed reduction. He has also had ˜10 subluxation episodes.

Physical Exam:

Apprehension with abduction/external rotation, even at low angles of abduction

Imaging:

X-rays show a moderate-sized Hill-Sachs lesion.
MRI shows an ALPSA (anterior labral periosteal sleeve avulsion) lesion with a type II SLAP lesion.
3D CT scan shows 25% loss of the inferior glenoid diameter.

Arthroscopic Findings:

Type II SLAP lesion with unstable biceps root.
Posterior HAGL lesion (capsular split variant) (Fig. 3-21).
25% glenoid bone loss.
Moderate-sized Hill-Sachs lesion.
We performed an arthroscopic repair of the posterior HAGL lesion (Fig. 3-22) and an arthroscopic SLAP repair. Then, we repositioned and reprepped the patient and did an open Latarjet reconstruction.

FIGURE 3-21 Right shoulder, anterosuperolateral viewing portal. A posterior HAGL lesion (capsular split variant) is identified. G, glenoid; H, humeral head; P, posterior capsule.

FIGURE 3-22 Right shoulder, anterosuperolateral viewing portal. Posterior HAGL lesion (capsular split variant) has been repaired arthroscopically with side-to-side sutures. G, glenoid; H, humeral head; P, posterior capsule.

Pearls, Pitfalls, and Decision-making:

This patient has 25% glenoid bone loss and plans to continue with vigorous competitive athletic activities, so he definitely requires a Latarjet reconstruction.
A SLAP lesion associated with anterior instability should be repaired, since SLAP repair increases the anterior capsular stiffness of the shoulder. And of course, the preferred means of SLAP repair is arthroscopic.
Because of the high incidence of additional pathology associated with anterior instability that has significant bone loss, we always do a diagnostic arthroscopy prior to the open Latarjet. If we had not done an arthroscopy in this case, we would have missed a very important component of his pathology, the posterior HAGL lesion, that likely would have remained symptomatic if it had not been discovered and repaired. In addition, we would have missed the SLAP lesion, which is a component of the anterior instability and should be repaired.
Total duration of dislocation can suggest whether an instability can be addressed arthroscopically or whether it will require a Latarjet reconstruction with coracoid bone graft. We have found that a total dislocation time of 5 hours or more generally causes enough bone compression on the glenoid and humeral sides of the joint that a Latarjet procedure will be required if one follows the usual bone loss criteria (loss of >25% of the inferior glenoid diameter requires a Latarjet).³ In this patient, his documented dislocation time of at least 2 hours for each of three dislocations (total 6 hours of total dislocation time) puts him into a category that will probably require Latarjet reconstruction.
Since the open Latarjet is usually performed in a beach chair position, surgeons might prefer to do their preliminary arthroscopy in the beach-chair position. This would allow them to more easily transition from the arthroscopic portion of the case to the open part of the case. However, the beach-chair position for shoulder arthroscopy is well known to be a very difficult position from which to repair posterior labral or capsular pathology. Therefore, we always do the arthroscopic part of the case in the lateral decubitus position and then reposition and redrape the patient in the beach-chair position for the open procedure.

History:

A 21-year-old college football player (wide receiver) with initial anterior dislocation of the left (nondominant) shoulder 1½ years ago. During the past season, the shoulder dislocated or subluxed during every game, but the athlete continued to have an outstanding season and was voted to the All-American team.
He is a top professional football prospect at wide receiver.

Physical Exam:

Positive apprehension with combined abduction and external rotation

Imaging:

Plain radiographs demonstrate a large Hill-Sachs lesion on the AP view (Fig. 3-23A) and suggest glenoid bone loss on the axillary view (Fig. 3-23B).
MRI shows an ALPSA lesion (medialized Bankart lesion) (Fig. 3-24A) and a SLAP lesion (Fig. 3-24B).
En face view on 3D CT scan shows ˜30% loss of the inferior glenoid diameter in comparison with the opposite (normal) side (Fig. 3-25).

Arthroscopic Findings:

A type II SLAP lesion was repaired with LabralTape (Arthrex, Inc., Naples, FL) and a BioComposite PushLock anchor (Arthrex, Inc., Naples, FL) (Fig. 3-26).
There was an inverted-pear glenoid with an anteriorly subluxed humeral head (Fig. 3-27).
Hill-Sachs lesion was seen to engage the anterior glenoid when the arm was brought into abduction and external rotation (Fig. 3-28).
Following arthroscopic SLAP repair, an open Latarjet reconstruction was performed (Fig. 3-29).

FIGURE 3-23 A: AP x-ray shows large Hill-Sachs lesion. B: Axillary x-ray suggests glenoid bone loss.

Pearls, Pitfalls, and Decision-making:

Arthroscopy must be performed prior to the open Latarjet reconstruction in order to discover and repair concomitant pathology, in this case, a SLAP lesion.
- An intact superior labrum contributes to mechanical stiffness and thereby enhances the instability repair. Therefore, a SLAP lesion that is discovered in a patient with anterior instability must be repaired.
- Latarjet reconstruction addresses both the glenoid bone defect and the humeral bone defect (Hill-Sachs lesion) by a combination of lengthening the articular arc of the glenoid plus providing a posteriorly directed force by virtue of the sling effect of the conjoined tendon. Therefore, no additional surgical procedures (such as remplissage or humeral bone graft) need to be directed toward the Hill-Sachs lesion whenever a Latarjet reconstruction is done.

FIGURE 3-24 Left shoulder MRI. A: ALPSA lesion shows capsule healed in a medialized position. B: Type II SLAP lesion.

History:

A 32-year-old male who is an oilfield worker.
He went out for a few drinks with friends. He says he was “feeling pretty good” when he tripped and fell onto his outstretched left arm. The next morning, he had pain and decreased motion in the left shoulder but he went to work and continued to work for 2 more weeks.
At 2 weeks postinjury, he went to an orthopaedic surgeon who x-rayed the left shoulder and found that the patient had a locked anterior dislocation. We first saw him at 3 weeks postinjury.

FIGURE 3-25 En face view of the glenoid on 3D CT scan shows 30% loss of inferior glenoid diameter in comparison with the opposite (normal) side.

FIGURE 3-26 Type II SLAP lesion was repaired with LabralTape (Arthrex, Inc., Naples, FL) and a knotless BioComposite PushLock anchor (Arthrex, Inc., Naples, FL). BT, biceps tendon; G, glenoid.

FIGURE 3-27 Left shoulder viewed from an anterosuperolateral portal shows an inverted pear glenoid. G, glenoid; H, humeral head.

Physical Exam:

Subjectively, the patient complains of some mild tingling in digits 1, 2, and 3 of the left hand. However, two-point discrimination is normal. Sensory and motor examinations are otherwise normal.
Brachial and radial pulses are normal.
Active and passive elevation is 45°. He can externally rotate to neutral.
He has loss of the normal contour of the left shoulder consistent with anterior shoulder dislocation.

FIGURE 3-28 Anterosuperolateral viewing portal shows the Hill-Sachs lesion engaging the anterior glenoid with combined abduction and external rotation. G, glenoid; HSL, Hill-Sachs lesion.

FIGURE 3-29 Postoperative Grashey (A) and axillary (B) x-rays show two screws securing the coracoid bone graft.

Imaging:

X-rays show a locked subcoracoid anterior dislocation of the left shoulder, associated with a large Hill-Sachs lesion (Fig. 3-30).
3D CT scan confirms the large Hill-Sachs lesion and also suggests a loss of about 20% of the inferior glenoid diameter (Fig. 3-31).

FIGURE 3-30 Plain x-rays. A: AP view shows a locked subcoracoid anterior dislocation of the left shoulder. B: Axillary view shows a large Hill-Sachs lesion, which is locked onto the anterior rim of the glenoid.

Arthroscopic Findings:

In the operating room, a closed reduction was attempted under fluoroscopic C-arm control. However, the humeral head was completely locked on the anterior rim of the glenoid, and it was impossible to reduce.
We did not think that a meaningful arthroscopic examination could be carried out with a locked subcoracoid dislocation, so we proceeded to perform an open reduction with open Latarjet reconstruction.

FIGURE 3-31 3D CT scan. A: Posterior projection of the humerus shows a large Hill-Sachs lesion. B: En face view of the glenoid shows that there is ˜20% loss of the inferior glenoid diameter.

Pearls, Pitfalls, and Decision-making:

With attempted closed reduction under C-arm, there was absolutely no motion of the humerus relative to the glenoid. It was obvious that closed reduction or arthroscopic-assisted closed reduction would not work. So we went straight to open reduction and Latarjet reconstruction through a deltopectoral incision. Latarjet was deemed necessary because of the large amount of bipolar bone loss.
The subscapularis and anterior capsule were extremely tight, and the only way to reduce the shoulder was to take down the entire subscapularis and the anterior capsule from their humeral attachments. After fixation of the coracoid graft and reattachment of the capsule to the native glenoid, we repaired the lower half of the subscapularis to the humerus by passing it inferior to the coracoid graft. We repaired the upper half of the subscapularis to the humerus by passing it superior to the coracoid graft. Since we had detached the entire subscapularis in order to reduce the shoulder, we thought it was important to have an extremely secure repair of the subscapularis to the humerus. Therefore, we repaired each half of the subscapularis to the humerus with a load-sharing rip-stop construct.
At 4 months post-op, the patient had full active and passive range of motion and excellent strength. His x-rays at 4 months post-op showed that the coracoid graft was beginning to show radiographic evidence of uniting to the anterior glenoid (Fig. 3-32).

REMPLISSAGE

The Off-track (Engaging) Hill-Sachs Lesion: When Is Remplissage Indicated?

Most engaging Hill-Sachs lesions are associated with significant bone loss (≥25%) on the glenoid side. When that is the case, these off-track engaging Hill-Sachs lesions are adequately treated by Latarjet reconstruction and will no longer engage after such surgery.

However, the surgeon sometimes encounters Hill-Sachs lesions that will engage the anterior glenoid rim even though there is not a significant glenoid bone loss (i.e., the glenoid bone loss is <25% of the inferior glenoid diameter). We call such lesions “off-track” Hill-Sachs lesions,⁴ and we have found that they are best treated by a combined arthroscopic Bankart repair and arthroscopic remplissage (insetting of the capsule and rotator cuff tendon into the
Hill-Sachs defect to make it an extra-articular defect that can no longer engage).

FIGURE 3-32 (A) AP and (B) axillary x-rays show good position of the coracoid bone graft, which is beginning to unite to the anterior glenoid.

Determining whether a Hill-Sachs lesion is “on-track” (nonengaging) or “off-track” (engaging) requires a bit of simple math, but it is not complicated and can be easily computed in the operating room from measurements taken at the time of surgery.

The “glenoid track” is a concept that must be understood if one is to fully understand how to calculate whether a Hill-Sachs lesion is “off track.”⁷ The glenoid track can be thought of as the imprint or “track” that the glenoid would make on the humerus as the arm is abducted in maximum external rotation. Think of the “footprint” that the surface of the glenoid makes on the humerus where the two bones come into contact. Then, imagine the continuous trail of consecutive “footprints” that combine as a moving contact surface between the two bones as the arm is abducted in full external rotation (Fig. 3-33A). This continuous trail of footprints is the “glenoid track.”

If there is a glenoid defect, the glenoid track narrows. When there is not any glenoid bone loss, the glenoid track is typically 83% of the diameter of the inferior glenoid (because the posterior glenoid pushes the cuff attachments 17% of the glenoid width posteriorly as the arm goes into forward abduction in external rotation). If there is a glenoid defect, then the glenoid track is narrowed by the width of the defect, so that the glenoid track (GT) = 0.83D -d where D = diameter of glenoid and d = width of glenoid defect (Fig. 3-33B, C).

Hill-Sachs lesions typically occupy the part of the humerus that is in contact with the glenoid track. The larger the Hill-Sachs becomes, the closer it gets to the medial margin of the glenoid track. Once the Hill-Sachs lesion reaches the point where it extends medial to the medial margin of the glenoid track, the humeral articular surface is no longer supported by the anterior glenoid margin and the humerus “falls off” the edge of the glenoid, which then engages the Hill-Sachs. At that point, we call it an “off-track” Hill-Sachs lesion (Fig. 3-34).

This is in contradistinction to an “on-track” Hill-Sachs lesion in which the medial margin of the Hill-Sachs lesion is lateral to the glenoid rim and the humeral articular surface is well supported by the anterior glenoid rim throughout the range of motion (Fig. 3-35).

The importance of the “off-track” Hill-Sachs lesion is that it may exist in association with a glenoid that does not have significant bone loss (i.e., <25% glenoid bone loss). In such a case, if an arthroscopic Bankart repair alone is done to address the instability, the Hill-Sachs lesion will still be able to engage the anterior glenoid rim and cause recurring instability, as we have demonstrated in the biomechanics lab.⁸ We have also demonstrated in the biomechanics lab that remplissage will eliminate engagement of “off-track” Hill-Sachs lesions at the same time that it significantly increases the biomechanical stiffness of the repair construct.⁸

Therefore, remplissage is our preferred technique for arthroscopically addressing the Hill-Sachs defect in patients with anterior instability who have an “off-track” Hill-Sachs in association with <25% glenoid bone loss. But in order to implement this arm of the treatment paradigm, the surgeon must be able to calculate whether or not the Hill-Sachs is “off-track.” So how is that done?

The Hill-Sachs Lesion: Is It On Track or Off Track?

As we have stated, in patients who have <25% glenoid bone loss in association with an off-track Hill-Sachs lesion, we prefer to treat them with a combination of arthroscopic Bankart repair and arthroscopic remplissage. We have previously explained how glenoid bone loss can be measured arthroscopically or from a 3D CT scan (Fig. 3-36).⁷ Similarly, one can measure the Hill-Sachs interval (HSI) and calculate the glenoid track either arthroscopically or from a 3D CT scan (Fig. 3-37). One can then deduce whether the Hill-Sachs lesion is off-track (engaging) or on-track (nonengaging).

FIGURE 3-33 A: At any point in shoulder motion, there is a contact point between the glenoid and the humeral articular surface, as shown by the glenoid outline in this schematic. As the arm is abducted in maximum external rotation, these individual contact “footprints” merge into a continuous “track” of contact on the humeral articular surface. This zone of contact on the humerus is defined as the “glenoid track.” B: When there is no glenoid bone loss, the glenoid track is 83% of the inferior glenoid diameter (0.83D). The contact between the glenoid articular surface and the humeral articular surface is not 100% of the glenoid diameter because the posterior glenoid rim pushes the rotator cuff attachments 17% posteriorly. C: When there is a glenoid defect, the glenoid track is reduced by the width of the defect. In this schematic, the width of the defect is “a,” so that the glenoid track in this case would be 0.83D – a, which is the length of the line “b” in this figure.

FIGURE 3-34 The medial margin of the Hill-Sachs lesion extends medial to the glenoid rim, allowing the Hill-Sachs lesion to engage the anterior glenoid rim. This is an “off-track” Hill-Sachs lesion. GT, glenoid track; d, glenoid defect.

FIGURE 3-35 The medial margin of the Hill-Sachs lesion is located lateral to the glenoid rim, so the Hill-Sachs lesion cannot engage the anterior glenoid rim. This is an “on-track” Hill-Sachs lesion. GT, glenoid track; d, glenoid defect.

FIGURE 3-36 Glenoid bone loss can be quantified with a three-dimensional computed tomography of the (A) normal and (B) affected extremities. The percentage of glenoid bone loss can be easily calculated on the en face view by comparing the inferior glenoid diameter of the normal side to that of the affected side.

FIGURE 3-37 Case with no bony defect of glenoid (A) and medium-sized Hill-Sachs lesion (B). By use of the contralateral glenoid as a reference (100%), 83% width is determined, which is the distance from the medial margin of the footprint of the rotator cuff to the medial margin of the glenoid track. Dotted line G indicates the location of the medial margin of the glenoid track. Dotted line R represents the medial margin of the rotator cuff attachments. This Hill-Sachs lesion is on track because it lies totally within the glenoid track.

The 3D CT scan can be used for obtaining these measurements. In terms of the glenoid, there are two important measurements:

1. The diameter (D) of the intact inferior glenoid (i.e., the diameter before any bone loss, either traumatic or attritional) and

2. The width (d) (Fig. 3-38) of the bone loss from the anterior glenoid (either attritional from compression or erosion due to repetitive dislocations, or traumatic with a bony Bankart fragment).

Yamamoto et al.⁷ have shown that the glenoid track width (GT) can be calculated as follows:

GT = 0.83D – d

The inferior glenoid diameter (D) can easily be measured from the en face 3D view of the normal glenoid (see Fig. 3-36A). The width of glenoid bone loss (d) can be calculated by subtracting the width of the inferior glenoid diameter on the involved side (D₁) from the inferior glenoid diameter on the normal side (D):

d = D – D₁

Now that we know both D and d, we can calculate the width of the glenoid track (GT = 0.83D – d).

FIGURE 3-38 Case with bony defect of glenoid (A) and large Hill-Sachs lesion (B). By use of the contralateral glenoid as a reference (100%), 83% width is determined (black double-headed arrow). Then, the defect width (d) is subtracted from this 83% length to obtain the glenoid track width for this case (white double-headed arrow). Dotted line R represents the medial margin of the rotator cuff attachments. It should be noted that there is normally an intact “bone bridge” between the cuff attachments and the lateral border of the Hill-Sachs lesion. Dotted line G1 indicates the location of the medial margin of the glenoid track. If there had been no glenoid bony defect, the medial margin of the glenoid track would have been dotted line G2. In this case, the Hill-Sachs lesion extends medially beyond the medial margin of the glenoid track (dotted line G1), so this is an offtrack lesion.

The only thing that remains to be determined is whether or not the medial aspect of the Hill-Sachs lesion extends medial to the glenoid track, and if it does, then the Hill-Sachs lesion is off-track since the anterior glenoid rim will engage the Hill-Sachs lesion (see Fig. 3-34).

In determining the medial extent of the Hill-Sachs lesion, it is useful to keep in mind the concept of the Hill-Sachs interval (HSI), which is the width of the Hill-Sachs lesion (HS) plus the width of the bone bridge (BB) between the rotator cuff attachments and the lateral aspect of the Hill-Sachs lesion:

HSI = HS + BB

If HSI > GT, the Hill-Sachs lesion is off-track and will engage the anterior glenoid. If HSI < GT, the Hill-Sachs lesion is on track and will not engage the anterior glenoid (see Fig. 3-35).

The problem with using the 3D CT scan to measure HSI is that the bony ridge where the posterior cuff attaches is often indistinct and very difficult if not impossible to accurately locate on the CT scan. Therefore, we prefer to obtain all our measurements arthroscopically.

In obtaining arthroscopic measurements, we first look at the glenoid through an anterosuperolateral portal. Through a posterior working portal, we insert a calibrated
probe to measure the distance from the bare spot of the glenoid to the posterior glenoid rim. This measurement gives us the radius (R) of the glenoid. The diameter of the inferior glenoid is then calculated by doubling the radius:

D = 2R

To calculate the glenoid bone loss (d), we measure two distances: the distance from the glenoid bare spot to the posterior glenoid rim (R₁) and the distance from the bare spot to the anterior glenoid rim (R₂). Glenoid bone loss (d) is then calculated:

d = R₁ – R₂

(Fig. 3-39)

The glenoid track width is:

GT = 0.83 D – d

Since D = 30 and d = 5 in this case, GT = 0.83(30) – 5, or GT = 19.9 mm.

Next, we arthroscopically determine the width of the Hill-Sachs interval (HSI) by measuring the width of the Hill-Sachs lesion (HS) and adding it to the width of the bone bridge (BB) at the same level:

HSI = HS + BB

(Fig. 3-40)

Since HS = 12 and BB = 12 HSI = 24 mm.

Once again, we compare the width of the glenoid track (GT) to the width of the Hill-Sachs interval (HSI). If HSI > GT, the Hill-Sachs lesion is off-track and will engage the anterior glenoid, and an arthroscopic remplissage must be performed in addition to an arthroscopic Bankart repair to prevent engagement. However, if HSI < GT, an arthroscopic Bankart repair alone will suffice. In this case, HSI (24 mm) > GT (19.9 mm). Therefore, this Hill-Sachs lesion is off-track and will require arthroscopic remplissage in addition to arthroscopic
Bankart repair. We have confirmed the validity of this paradigm for arthroscopic remplissage in a recent biomechanical study.⁸ Furthermore, a recent clinical study confirmed that offtrack shoulders were at much higher risk of recurrent instability with isolated arthroscopic Bankart repairs.⁶

FIGURE 3-39 Left shoulder, anterosuperolateral viewing portal. The calibrated probe, with 5-mm hash marks, has been introduced through a posterior portal. The radius of the glenoid is the distance from the bare spot of the glenoid to the posterior glenoid rim, or 15 mm (three hash marks). There has been some anterior bone loss, and the distance from the bare spot to the anterior glenoid rim is only 10 mm, indicating that there has been a 5-mm anterior glenoid bone loss.

FIGURE 3-40 A: The width of the Hill-Sachs lesion is measured sequentially by the 4-mm tip of the probe. The Hill-Sachs lesion has a width equal to three probe tips: 3 × 4 mm = 12 mm. B: The width of the bone bridge between the posterior cuff attachments and the Hill-Sachs lesion (H-S) is found to span three probe tips: 3 × 4 mm = 12 mm. G, glenoid.

Remplissage Techniques

Remplissage of a Hill-Sachs lesion consists of insetting the infraspinatus tendon into the Hill-Sachs defect, thereby making the defect extra-articular and preventing engagement with the anterior glenoid rim (Fig. 3-41).

Technique of Arthroscopic Remplissage

This procedure, like all of our arthroscopic shoulder procedures, is done with the patient in the lateral decubitus position. We begin with three standard portals: posterior, anterior, and anterosuperolateral.

Viewing from an anterosuperolateral portal, the glenoid is visualized and evaluated for bone loss (Fig. 3-42). If there is >25% loss of the inferior glenoid diameter, the procedure is converted to an open Latarjet reconstruction. The arm is removed from its balanced suspension and is rotated as it is brought through a range of abduction. This allows assessment of the position of engagement of the Hill-Sachs lesion (Fig. 3-43). We then use a calibrated probe to take all the necessary measurements to determine significant bone loss. If there is no significant glenoid bone loss and if the Hill-Sachs lesion is calculated to be off-track, we proceed with an arthroscopic Bankart repair and remplissage.

FIGURE 3-41 Schematic of remplissage for a Hill-Sachs lesion. A: Axial schematic of a Hill-Sachs lesion. B: Anchors are placed into the Hill-Sachs defect. C: Sutures are passed through the infraspinatus tendon and tied to inset the tendon into the defect. Inset of the infraspinatus into the defect converts the Hill-Sachs lesion to an extra-articular defect. D: Sagittal oblique view demonstrates the mattress stitches between the two anchors that have been tied using a doublepulley technique. G, glenoid; H, humeral head; IS, infraspinatus tendon.

The Bankart lesion is addressed first, with anchor placement and suture passage, but the knots are not tied until after the remplissage anchors have been placed. The reason for this sequence is that the anteriorly directed forces associated with placing suture anchors in the back of the humerus can disrupt the suture fixation of the labrum if the Bankart knots are tied before placing the Hill-Sachs anchors.

For the remplissage, the bone bed in the Hill-Sachs lesion is prepared by means of ring curettes placed through a posterior working portal while viewing from the anterosuperolateral portal (Fig. 3-44).

Next, the subacromial space is prepared. Bursa and fibrofatty tissue are removed by alternating between posterior and lateral portals for viewing and working. Care is taken to clear out the posterior gutter so that the entire infraspinatus tendon can be visualized.

FIGURE 3-42 Left shoulder, anterosuperolateral portal demonstrating absence of glenoid bone loss in an individual with anterior glenohumeral instability. A: A calibrated probe inserted from a posterior portal measures a distance of 10 mm from the bare area to the posterior glenoid rim. B: The distance from the anterior glenoid rim to the bare area is also 10 mm. G, glenoid; H, humeral head.

The arthroscope is then reinserted intra-articularly through the anterosuperolateral viewing portal. The concept of our technique of remplissage is to inset the infraspinatus tendon into the Hill-Sachs defect, in contradistinction to other methods that insert capsule and muscle into the defect. This means that our sutures must obtain fixation more laterally than these other techniques, in order to ensure capture of the tendon rather than muscle.

Continuing to view through an anterosuperolateral portal, we next place two spinal needles percutaneously through the infraspinatus tendon, at a 30° to 45° angle to the Hill-Sachs lesion. The humerus may be internally or externally rotated to provide a better angle of approach to the bone (Fig. 3-45A). We then use a 5-mm transtendon metal cannula (Arthrex, Inc., Naples, FL) parallel to each of the two spinal needles to place two suture anchors, one at the top of the Hill-Sachs lesion and the other at the bottom (Fig. 3-45B, C). A Spear drill guide (Arthrex, Inc., Naples, FL) is used to stabilize the drill for creating the sockets for insertion of double-loaded BioComposite SutureTak suture anchors (Arthrex, Inc., Naples, FL). In some cases, anchor placement requires an angle of approach that begins too far lateral for the anchors to be placed transtendon. In this case, the solution is to place the anchors through the posterior

portal, then perform retrograde retrieval of the sutures of each anchor through two separate transtendon passes with a Penetrator (Arthrex, Inc., Naples, FL) (Fig. 3-46). In either case, by placing the anchors transtendon or retrieving the sutures transtendon in this way, all four suture limbs from a given anchor will exit the same point in the tendon. Then, the double-pulley repair technique is used to complete the remplissage. However, prior to completing the remplissage, one should tie the knots for the Bankart repair, so that subacromial fluid extravasation during the remplissage will not compromise the space required for Bankart repair.

FIGURE 3-43 Left shoulder, anterosuperolateral viewing portal demonstrates a Hill-Sachs lesion. A: A calibrated probe inserted from a posterior portal estimates the depth of the lesion to be 5 mm. B: Removing the arm from traction and placing it in the 90-90 position demonstrates that the Hill-Sachs lesion does not engage the anterior glenoid. G, glenoid; H, humeral head.

FIGURE 3-44 Left shoulder, anterosuperolateral viewing portal demonstrating bone bed preparation of the Hill-Sachs lesion. A: A ring curette is introduced from a posterior portal and used to remove soft tissue. B: Completely prepared bone bed of a Hill-Sachs lesion. H, humeral head.

FIGURE 3-45 Left shoulder, anterosuperolateral viewing portal demonstrating percutaneous placement of suture anchors for remplissage. A: A spinal needle is used as a guide to establish the proper angle of approach to the Hill-Sachs lesion. B: An inferior anchor is placed transtendon with the use of a metal cannula. C: Using the same technique, a second anchor is placed in the bone bed superior to the first anchor. H, humeral head.

FIGURE 3-46 Right shoulder, anterosuperolateral portal demonstrating suture passage for remplissage using a retrograde technique. A: Sutures are seen exiting a posterior portal following anchor placement via the posterior portal. Using a spinal needle as a guide, the inferior sutures are passed through the infraspinatus tendon with a Penetrator (Arthrex, Inc., Naples, FL). B: The superior sutures are passed. H, humeral head.

FIGURE 3-47 Right shoulder demonstrating use of Spear guides to locate and protect remplissage sutures. A: External view shows Spear guides (blue arrow) in place over sutures passed through the infraspinatus tendon. B: Lateral subacromial view in the same shoulder. The Spear guide (blue arrow) protects the sutures as a shaver clears the bursa overlying the muscle and tendon. RC, rotator cuff.

To inset the infraspinatus tendon into the Hill-Sachs lesion, we use the same double-pulley technique that we use for PASTA repairs. This technique entails creating two double-mattress sutures between the two anchors by tying the sutures of one anchor to those of the other anchor. Subacromial viewing is done either through a posterior or a lateral subacromial portal, depending on which one gives the best view. Although a bursectomy has been previously performed in order to aid in visualizing the sutures, placing Spear guides over the sutures is helpful for protecting and locating the sutures (Fig. 3-47).

FIGURE 3-48 The double-pulley technique for remplissage in a right shoulder. A: Lateral subacromial viewing portal. Sutures from two anchors placed in a Hill-Sachs lesion are visualized in the subacromial space passing through the infraspinatus. B: A single blue suture limb from each anchor is retrieved and extracorporeally tied over an instrument. C: The suture limbs are cut, and the knot is delivered back into the subacromial space by pulling on the opposite blue suture limbs. D: The first knot (black arrow) now rests on the infraspinatus. The remaining suture limbs may be retrieved and tied as static knots to complete the double pulley. RC, rotator cuff.

One suture limb of a given color from each anchor is retrieved through the working cannula. Then, outside the patient’s body, these two suture limbs are tied to each other over the top of a rigid instrument by means of a six-throw surgeon’s knot. Next, the two corresponding “free” limbs are tensioned and pulled, using the suture anchors’ eyelets like pulleys, to pull the knot into the subacromial space and onto the top of the infraspinatus tendon (Fig. 3-48). Then, the two “free” limbs are tied together with a static six-throw surgeon’s knot using the Surgeon’s Sixth Finger Knot Pusher (Arthrex, Inc., Naples, FL). It should be noted that this second knot must be a static knot; a sliding knot cannot be tied here because the other two suture limbs of this pair have already been fixed with a knot that will prevent sliding. Finally, the two other suture pairs are tied with the double-pulley technique in the same way as the first two suture pairs, creating another double-mattress configuration. Then, we again look intra-articularly to be sure that the tendon has inset all the way into the Hill-Sachs lesion (Fig. 3-49).

Postoperatively, we keep the patient in a sling for 6 weeks and then begin a stretching program. We do not start strengthening until 12 weeks post-op. The rationale for the delayed strengthening is that for rehabilitation considerations, we view remplissage in the same way as an infraspinatus tendon repair, and for rotator cuff repairs, we do not allow strengthening until 12 weeks post-op. We have not observed clinically significant loss of internal or external rotation after remplissage. However, we have not done remplissage in an overhead athlete, and we suspect it would affect the amount of combined abduction-external rotation that could be achieved in the late cocking phase of throwing.

FIGURE 3-49 A: Right shoulder, anterosuperolateral portal demonstrating a Hill-Sachs lesion. B: Following a remplissage, the infraspinatus fills the defect so that the lesion is now extra-articular. C: Posterior subacromial viewing portal in the same shoulder after remplissage showing the mattress sutures tied with a double-pulley technique. G, glenoid; H, humeral head; IS, infraspinatus tendon; RC, rotator cuff.

One of the problems with the “double-pulley” technique of remplissage is that it can be very time consuming. We have been able to simplify our technique by using self-cinching knotless suture anchors (Knotless SutureTak; Arthrex, Inc., Naples, FL) with interlocking splices. Biomechanical testing has shown this construct to be even stronger than the double-mattress construct created by the double-pulley remplissage. Furthermore, we often perform the interlocking cinching part of the procedure in “blind” fashion, without directly visualizing the sutures in the subacromial space. In this way, we avoid a time-consuming subacromial bursectomy, which further shortens and simplifies the technique.

Knotless Interlocking Remplissage

Video 3-6 The Knotless SutureTak (Arthrex, Inc., Naples, FL) has been used since 2012 for arthroscopic labral repairs. It has a unique mechanism in which the end of a coreless suture is passed through soft tissue (e.g., labrum) and then shuttled back through a segment of its coreless sheath to create a one-way knotless splice that will not slip (Fig. 3-50).

Video 3-7 By interlocking the splices of the two knotless anchors used in remplissage, we can simplify the technique and strengthen the construct. The interlocking creates a knotless double-mattress construct between the two anchors. The cinching of the splices can be done with direct visualization in the subacromial space, but achieving satisfactory visualization in the posterolateral part of the subacromial space can be very time consuming. Therefore, we developed a “blind” technique of cinching down the remplissage that is quick and easy to perform, yet very strong and reliable.

The steps are as follows:

Two working cannulas are used, a straight posterior cannula that goes intra-articularly and a posterolateral cannula that goes into the subacromial space (Fig. 3-51A). An anterosuperolateral viewing portal is used. The surgeon should visualize intra-articularly while the subacromial portal is placed. A spinal needle identifies the proper angle of approach, which is ˜45° to the plane of the Hill-Sachs lesion. This angle assures that the tendon rather than the muscle is inset into the defect.

FIGURE 3-50 Method of fixation with Knotless SutureTak (Arthrex, Inc., Naples, FL). A: The suture from the anchor is passed through the soft tissue and then threaded through the loop of the suture threader. Inset: Sectioned anchor shows the segment of coreless suture that the threader traverses. B: The free end of the suture threader (black limb) is pulled in order to thread the splice. C: The splice is threaded and the suture is tensioned to create a knotless loop around the soft tissue. Inset: Sectioned anchor shows the section of coreless suture that has now been threaded. This enlarged portion of the suture creates a one-way selfcinching splice that can be tightened by pulling on the free suture end but cannot be loosened.

While viewing the Hill-Sachs, the surgeon introduces a switching stick adjacent to the spinal needle and watches the switching stick indent the tendon and capsule, signifying that the switching stick is just above the tendon. Then, the cannula and its cannulated introducer are delivered into the subacromial space by advancing them over the switching stick. When these are seen to indent the tendon and capsule, the cannula and its introducer are swept back and forth to create a “virtual space” above the tendon.

Two Knotless SutureTak anchors are placed near the medial margin of the Hill-Sachs lesion through the posterior working portal. Then, a Penetrator Suture Retriever (Arthrex, Inc., Naples, FL) is introduced through the subacromial cannula. It penetrates the infraspinatus tendon at a 45° angle and retrieves the working suture

and the passing suture from one of the anchors (Fig. 3-51B). The subacromial cannula is then angled ˜30° away from the previous anchor (and toward the other anchor), and the Penetrator Suture Retriever is again passed through the tendon to retrieve the other set of sutures. There should be a 1- to 2-cm tendon bridge between the two suture pairs that have been retrieved, so that a substantial bridge of tissue will be inset into the Hill-Sachs lesion when the splices are cinched down (Fig. 3-51C). The surgeon must be careful to keep the two sets of sutures separated.

FIGURE 3-51 Steps in performing knotless interlocking remplissage. A: Two working cannulas are used. A posterior intra-articular cannula is used for placing two anchors (Knotless SutureTak; Arthrex, Inc., Naples, FL) into the Hill-Sachs lesion, adjacent to the medial margin of the defect. A posterolateral subacromial cannula will be used for retrieving the sutures transtendon into the subacromial space. The cannula is swept to-and-fro just above the tendon to create a virtual space. B: A Penetrator Suture Retriever (Arthrex, Inc., Naples, FL) is passed through the infraspinatus tendon at a 45° angle to retrieve a set of sutures from one anchor. Then, the Penetrator is redirected to penetrate the tendon again (with a 1- to 2-cm bridge of tendon between the two sets of sutures). C: The two suture pairs have a tendon bridge between them. D: The working suture from anchor #1 is passed through the loop of the passing suture from anchor #2 and vice versa. E: The splices are threaded by pulling on the threading sutures. Then, the two loops are sequentially cinched down to inset the tendon into the Hill-Sachs defect. This creates a very strong knotless double mattress configuration.

Then, the working suture of anchor #1 is passed through the loop of the threading suture of anchor #2, and vice versa (Fig. 3-51D). The splices are threaded by pulling the free limb (nonlooped end) of the threading sutures until the entire threading suture has pulled through and is free of the anchor.

Next, the knotless loops are cinched down onto the tendon by reciprocally pulling on the two working sutures. As the knotless double-mattress sutures are tensioned over the infraspinatus tendon bridge, the surgeon will see the capsule being drawn into the Hill-Sachs defect, making it an extra-articular defect that is no longer capable of engaging the glenoid rim (Fig. 3-51E).

REMPLISSAGE CONUNDRA

History:

A 36-year-old male who has had four anterior dislocations over the past 5 years.
He is an avid recreational soccer player.
He works at a desk job as a computer software engineer.

Physical Exam:

Full range of motion
Normal strength
Apprehension in the 90-90 position

Imaging:

3D CT shows a Hill-Sachs lesion (Fig. 3-52).
MRI shows a Bankart lesion and Hill-Sachs (Fig. 3-53).

FIGURE 3-52 AP x-ray shows a Hill-Sachs lesion.

Arthroscopic Findings:

The Bankart lesion was actually an ALPSA lesion, in which the capsulolabral complex had healed in a medialized position (Fig. 3-54).
Glenoid bone loss was measured arthroscopically and was found to be 16% loss of the inferior glenoid diameter.
The Hill-Sachs interval (distance from medial rim of Hill-Sachs lesion to the articular side humeral attachment of the rotator cuff) was measured arthroscopically to be 18 mm.
The glenoid track was calculated to be 14.5 mm (0.83D – d).
Since the Hill-Sachs Interval (HSI) is greater than the glenoid track (GT), this is an off-track Hill-Sachs lesion.
An arthroscopic Bankart repair (Fig. 3-55) and an arthroscopic remplissage (Fig. 3-56) were performed.

FIGURE 3-53 MRI scan confirms a Bankart lesion and also shows a Hill-Sachs lesion.

FIGURE 3-54 Left shoulder, anterosuperolateral viewing portal. The torn capsulolabral complex has healed medial to the glenoid rim. H, humeral head.

FIGURE 3-55 Left shoulder, anterosuperior viewing portal. View of arthroscopic Bankart repair. G, glenoid; H, humeral head.

FIGURE 3-56 Left shoulder, anterosuperolateral viewing portal. Arthroscopic remplissage into the Hill-Sachs lesion converts the bone defect to an extra-articular defect. H, humeral head.

Pearls, Pitfalls, and Decision-making:

ALPSA lesions, with medialized healing of the capsulolabral complex, have been shown to be associated with a high rate of recurrent dislocation when treated solely with an arthroscopic Bankart repair. For this reason, it is important to achieve meticulous capsulolabral mobilization so that the labral margin “floats up” to the level of the glenoid rim (Fig. 3-57).
Mobilization of the capsulolabral complex must proceed until the subscapularis muscle belly is clearly visualized deep in the dissection (Fig. 3-58).
In mobilizing the labrum off the anterior glenoid, we use a 15° elevator for most of the dissection, but for dissection below the 6:30 position (in a left shoulder), a 30° elevator gives a more congruent approach to the glenoid neck.
Patients with >15% glenoid bone loss will present a very oblique approach for placement of anteroinferior suture anchors through a standard anterior portal. In this case, we used an accessory percutaneous trans-subscapularis (5 o’clock) portal, which gives a more direct approach for placement of the two most inferior anchors solidly into the anteroinferior glenoid.
For anchor placement, we remove a 2-mm strip of articular cartilage along the glenoid rim with a ring curette to assure better healing of the labrum to bone (Fig. 3-59).
This patient has another risk factor for recurrent instability (in addition to his ALPSA lesion) and that is an off-track Hill-Sachs lesion. A Hill-Sachs lesion is offtrack if the Hill-Sachs interval (HSI) is greater than the width of the glenoid track (GT). In this case, HSI = 18 mm and GT = 14.5 mm. Since AHI > HSI, this is an off-track lesion.
The glenoid bone loss is <25%, so by our paradigm, this instability can be repaired arthroscopically. However, since the Hill-Sachs lesion is an off-track lesion, we must perform an arthroscopic remplissage in addition to the arthroscopic Bankart repair.

FIGURE 3-57 Left shoulder, anterosuperolateral viewing portal. After mobilization, the labrum has “floated” up to the level of the glenoid rim. G, glenoid.

FIGURE 3-58 Left shoulder, anterosuperolateral viewing portal. After capsulolabral mobilization, the subscapularis muscle belly is visible deep to the capsule.

FIGURE 3-59 Left shoulder, anterosuperolateral viewing portal. A 2-mm strip of articular cartilage along the anterior glenoid margin is removed with a ring curette. G, glenoid; H, humeral head.

History:

A 19-year-old male college student who has had two anterior dislocations of the right shoulder. He does not feel that he can trust the shoulder, and he wants it “fixed.” Both parents are physicians and have expressed their hope that an arthroscopic repair can be done.

Physical Exam:

Full range of motion
Normal strength
Positive apprehension in combined abduction/external rotation

Imaging:

X-rays showed a moderate-sized Hill-Sachs lesion.
3D CT scan suggested that the Hill-Sachs lesion was off-track.
MRI scan showed a nondisplaced Bankart lesion.

Arthroscopic Findings:

Arthroscopic measurements confirmed that there was only a small amount of glenoid bone loss (Fig. 3-60) and that the Hill-Sachs lesion was off-track (Fig. 3-61).
Arthroscopic Bankart repair was performed along with arthroscopic remplissage, using a knotted double-pulley technique (Fig. 3-62).

FIGURE 3-60 Right shoulder, anterosuperolateral viewing portal. Nondisplaced Bankart lesion with minimal bone loss. G, glenoid.

Pearls, Pitfalls, and Decision-making:

This patient had two previous anterior dislocations. Each one was “out” for 2 hours prior to reduction, so he had a total time of dislocation of 4 hours. We have reported that in our practice, a cumulative dislocation time of >5 hours causes enough bone compression and erosion that a Latarjet procedure is necessary to adequately address the bone loss. In this patient, even though he has an off-track Hill-Sachs lesion, he can still be treated arthroscopically with an excellent chance of success. However, one more dislocation with a “dislocation time” of >1 hour would put him at risk for needing a Latarjet. So it makes sense to go ahead and treat him arthroscopically at this point.
Although there are now some very good knotless techniques for remplissage that expedite the procedure, the technique of creating a knotted double-pulley construct, as used in this patient, gives a strong and reliable reconstruction. For those surgeons that prefer knotted anchors, this repair is the best.

FIGURE 3-61 Right shoulder, anterosuperolateral viewing portal. Hill-Sachs lesion, which has been calculated, by arthroscopic measurements, to be an “off-track” lesion. H, humeral head.

FIGURE 3-62 Right shoulder, anterosuperolateral viewing portal. Final view of remplissage, after capsule and infraspinatus have been inset into the Hill-Sachs defect. H, humeral head.

History:

A 17-year-old football player (defensive tackle) was injured when another player landed on the back of the arm.
He reports a dislocation on the field, which reduced spontaneously after several minutes.
He completed the season in a Sully brace with pain.
He failed conservative routes and wished to proceed with surgery.

Physical Exam:

Positive labral findings including Jobe apprehension/relocation exam, O’Briens, and Mayo shear test.
Normal strength.

FIGURE 3-63 Axial MRI demonstrates a significant anterior glenoid labral tear, likely anterior glenoid bone loss, and a Hill-Sachs lesion on the posterior humeral head.

Imaging:

Plain films normal
MRI demonstrated significant anterior labral pathology as well as a Hill-Sachs lesion (Fig. 3-63).

Arthroscopic Findings:

The patient had a significant Bankart tear as well as significant glenoid bone loss anteriorly (Fig. 3-64).
A wide (but not too deep) Hill-Sachs was encountered as well (Fig. 3-65).
The Hill-Sachs as well as the Bankart lesions were both debrided and prepared for repair (Fig. 3-65).
The Bankart lesion was addressed first starting at the 6 o’clock position through a 5 o’clock portal (Fig. 3-66).
The FiberWire suture from the knotless 3.0 SutureTak anchor was then shuttled through the tissue (Fig. 3-67).
The suture is then shuttled back down into the splice locking mechanism within the body of the anchor (utilizing the 2.0 FiberLink shuttle suture) (Fig. 3-68).
The anchors for the remplissage are then passed through the infraspinatus tendon while visualizing intra-articularly through the ASL portal (Fig. 3-69).
The “double-pulley” construct is then completed on the subacromial side (Fig. 3-70) and the construct secured—thus securing the infraspinatus tendon down into the prepared Hill-Sachs lesion (Fig. 3-71).

FIGURE 3-64 A: The distance from the bare area to the posterior glenoid is ˜17 mm. B: The distance from the anterior glenoid to the bare area is ˜9 mm. Thus, the percentage glenoid bone loss is 8/34 = 0.24, or 24 bone loss. G, glenoid; H, humeral head.

Pearls, Pitfalls, and Decision-making:

This patient had a moderate amount of anterior glenoid bone loss. It measured ˜24% glenoid bone loss. Drs. Burkhart and Joe de Beer have shown that bone loss of 25% likely does better with Latarjet procedure. However, when adding a remplissage to these “borderline” cases, it is possible in some cases to restore stability, even in high-demand patients who would likely have failed a Bankart repair alone.
By performing the remplissage, this makes the Hill-Sachs essentially nonengageable.
In the presented technique, the remplissage anchors are placed independently in a transtendon fashion through the infraspinatus. No additional suture passage is necessary in this method. However, a potential
pitfall of this method is placing the anchors (and thus sutures) too medial within the muscular portion of the infraspinatus rather than more laterally in the tendinous portion.
Another potential pitfall is that if the anchors are placed laterally through the infraspinatus (as is appropriate), the insertion angle on the humerus can be too steep and result in penetration of the humeral head. A pearl to avoid this complication is to utilize the stout anchor inserter guide to push down on the inserter to force a good angle into the Hill-Sachs defect. Arm rotation can also help with this angle. It is imperative that the surgeon be sure not to penetrate the humeral head with anchor drilling or insertion!
When the anchors are placed transtendon, the inserters (and inserter guides) are left in position. Thus, when you go subacromial to retrieve the sutures (for creation of the double-pulley construct), the sutures are protected from the shaver by the metal inserter guide. Once both guides are identified, they can be pulled out and then the suture construct can be completed.

FIGURE 3-65 A: The Hill-Sachs lesion is prepared from the posterior portal while visualizing through the ASL portal. B: The glenoid is prepared through the anterior portal with an Arthrex Torpedo shaver. HSL, Hill-Sachs lesion; H, humeral head; G, glenoid.

FIGURE 3-66 The inferior glenoid anchor is placed through a 5 o’clock portal. H, humeral head; G, glenoid.

FIGURE 3-67 The FiberWire suture from the 3.0 Knotless SutureTak anchor is passed through the inferior labrum utilizing a shuttle suture passer (ReelPass; Arthrex, Inc.; Naples, FL). G, glenoid; H, humeral head.

FIGURE 3-68 A: The tapered end of the FiberWire suture is passed back into the splice locking mechanism within the body of the anchor. B: The suture is then pulled thus tightening the suture loop around the labrum and securing the labrum to the glenoid. G, glenoid; H, humeral head.

FIGURE 3-69 A: The Hill-Sachs lesion is visualized from the ASL portal. B, C: The inferior and superior anchors are placed in a transtendon fashion (through the infraspinatus) lateral to the posterior portal. D: The inserter guides are not removed thus protecting the underlying sutures from the shaver during the subacromial debridement. H, humeral head; HSL, Hill-Sachs lesion.

FIGURE 3-70 The FiberWire from the inferior anchor is passed into the splice of the superior anchor, and the FiberWire from the superior anchor is passed into the splice of the inferior anchor. The sutures are pulled snug to the infraspinatus tendon but not tightened yet. IS, infraspinatus.

HAGL (HUMERAL AVULSION OF GLENOHUMERAL LIGAMENTS) LESIONS IN ANTERIOR INSTABILITY

HAGL lesions can be missed on diagnostic arthroscopy unless the surgeon is vigilant in specifically looking for them. They are best visualized through an anterosuperolateral portal. Typically, the subscapularis is visible through the defect in the retracted capsule. The lesion may consist entirely of a capsular avulsion from the bone of the proximal humerus (Fig. 3-72), or it may predominantly be a capsular split that extends out to the humeral attachments with only a minor avulsion from the bone (Fig. 3-73). HAGL lesions may occur in combination with Bankart lesions.

FIGURE 3-71 A: While visualizing from intra-articularly, the repair site is visualized from the ASL portal. B: The suture limbs are then tightened thus compressing the infraspinatus tendon down into Hill-Sachs defect. HSL, Hill-Sachs lesion; H, humeral head.

FIGURE 3-72 Right shoulder, anterosuperior viewing portal. The subscapularis muscle is visible through the defect created by the HAGL lesion. The anterior capsule has been avulsed from bone. SSc, subscapularis muscle; C, capsule; H, humeral head.

FIGURE 3-73 A: Left shoulder, anterosuperolateral viewing portal demonstrates a capsular split variant of a reverse humeral avulsion of the glenohumeral ligaments (black arrow). B: Up-close view demonstrates muscle visible (white arrow) underlying the capsular split. G, glenoid; H, humeral head.

HAGL lesions that extend inferiorly to or beyond the 5 o’clock position can be very difficult to repair arthroscopically due to the extreme obliquity of the angle of approach that is required for suture anchor placement (the “killer angle”) (Fig. 3-74). Furthermore, we have seen HAGL lesions that extend posterior to the 6 o’clock position, necessitating both anterior and posterior portals for repair.

FIGURE 3-74 The killer angle. A: External view in a left shoulder demonstrates the location of the medial low anterior portal (black arrow). Note: This portal begins medial to the 5 o’clock portal, which is normally directly inferior to the anterior portal. B: Anterosuperolateral viewing portal demonstrates spinal needle (white arrow) location in the glenohumeral joint. C: Up-close view shows the killer angle. The white line parallels the trajectory of the spinal needle. The blue line parallels the humeral head. The angle between these two lines is acute with little room for error. Thus, the phrase “killer angle.” A, anterior portal; ASL, anterosuperolateral portal; H, humeral head; HAGL, humeral avulsion of the glenohumeral ligaments.

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