Anterior Instability: Open Bankart Repair

Michael J. Pagnani

Justin E. Hill

INDICATIONS

For more than a century, open Bankart repair has demonstrated almost uniformly excellent results in the treatment of anterior shoulder instability. After open capsular repair, postoperative recurrence rates have generally been reported between 0% and 5% in unselected populations.¹^, ²^, ³^, ⁴^, ⁵^, ⁶^, ⁷ ^and ⁸ Yet, due to the popularity of arthroscopic methods of stabilization,⁵ open capsular repairs have been largely neglected in the training of most orthopaedic surgeons. However, arthroscopic repairs have been plagued by unacceptably high recurrence rates in high-risk groups such as contact athletes, patients with capsular laxity, and those with bone loss of the humeral head or glenoid fossa.⁹^, ¹⁰^, ¹¹^, ¹²^, ¹³^, ¹⁴^, ¹⁵^, ¹⁶ ^and ¹⁷ As a result, it is now commonly recommended that such at-risk patients be treated with a bone-augmentation technique such as the Latarjet procedure. While biomechanical studies suggest that bony defects around the shoulder should have negative effect on clinical outcomes after capsular procedures, open Bankart repair has been shown in multiple studies to have excellent outcomes even in patients with bony deficiency of the glenoid and humeral head.¹^, ² ^and ³^,⁵^,¹⁸ In our opinion, the impulsive surgical decision to move from an arthroscopic Bankart repair to a bone-block procedure such as a Latarjet is essentially going from “point A to point C.” Such an algorithm ignores “point B”—open Bankart repair.

The hope that the results of “modern” techniques for arthroscopic stabilization for anterior shoulder instability would approximate those reported for open capsular repair has not been realized; recurrence rates for arthroscopic repair have been shown in recent meta-analyses to continue to exceed the historical rates for open stabilization. Hohmann et al,¹⁹ in a recent systematic review, noted that results reported in the literature for arthroscopic stabilization between 2005 and 2015 had not improved statistically when compared to results reported between 1995 and 2004. Alkaduhimi et al,²⁰ in another systematic review published in 2016, concluded, “Despite advances in surgical techniques and devices during the last 20 years,…the recurrence rate for arthroscopic shoulder stabilization has only marginally decreased.”

These higher failure rates have persisted despite careful patient selection in which many arthroscopic studies exclude high-risk groups.¹³^,²¹^, ²²^, ²³ ^and ²⁴ The preponderance of highly selected patients in reports of the results of arthroscopic stabilization makes comparison with the outcomes of open Bankart repair without such exclusions problematic. In addition, the dearth of case series on the results of open stabilization from experienced surgeons at leading centers of shoulder surgery over the past 20 years does not permit adequate assessment of “modern” open techniques for such comparisons. Despite these limitations, no fewer than seven separate meta-analyses have concluded that the results of open stabilization have been superior to those of arthroscopic stabilization.¹³^,¹⁵^,¹⁹^,²⁰^,²⁵^, ²⁶ ^and ²⁷ For example, Hohmann et al¹⁹ found a 37% higher risk of recurrent instability with arthroscopic techniques compared to open methods.

Open stabilization has several advantages over arthroscopic repair that may well explain the differences in recurrence rates:

Open methods allow the surgeon to completely free the capsule from the subscapularis tendon to precisely tension the capsule without adherence to the subscapularis.
The rotator interval can be better visualized and tensioned via an open technique; open rotator interval closure does not have the same effect on shoulder translation or rotation as arthroscopic closure.
The thickness of the capsule can be doubled by overlapping the capsule during open repair.
The arm can be optimally positioned for open repair.
Open techniques allow for repair of the capsule and labrum with knots tied extra-articularly, eliminating concern about suture impingement on the articular surfaces of the shoulder.

The resurgence of interest in bone-block procedures such as the Latarjet has, in our opinion, significant pitfalls:

Unless performed in a modified form, they do not address capsular laxity or capsulolabral separation.
They carry a high risk of complications from hardware loosening or nonunion.
Revision surgery is difficult.
There is a high incidence of postoperative arthrosis.

While there is little doubt that such procedures are effective at restoring stability, complication rates after the Latarjet can be high. In an observational review of patients referred to our office for continued shoulder dysfunction after a Latarjet procedure performed at other institutions,²⁸ we noted that 21 of 27 patients had a nonunion of the transferred coracoid. The vast majority of those with nonunion had broken screws. Only five of the 21 patients with coracoid nonunion had instability complaints (leading one to wonder what clinical role—if any—the bone-block actually plays in restoring stability). More than half of the patients had radiographic evidence of osteoarthritis, and nerve injuries occurred in six patients. While this was a selected population that sought our assistance after problems with the procedure, it is clear that significant complications are not uncommon—especially when the Latarjet is performed by a surgeon who is inexperienced with the technique.

Large defects of the humeral head and/or glenoid are infrequently encountered in the treatment of anterior shoulder instability—even in tertiary referral shoulder practices such as ours with a large percentage of contact athletes. Over a 6-year period,²⁹ we encountered only nine patients with large (>4 cm long and 0.5 cm deep) humeral head defects and only four with large (>20% of the glenoid diameter) defects of the glenoid.

Based on the low rates of recurrence, motion loss that was equal to or better than that reported for bone-block procedures, and the seemingly self-evident premise that the complication rate of capsular repair alone should be lower than that of a bone-augmentation procedure, it appears that bone-block or grafting procedures are not necessary in the majority of patients with bony defects of the glenoid and/or humeral head if they are treated with contemporary techniques of open stabilization.

The general indications for surgical treatment of recurrent anterior shoulder instability are highly subjective. They include a desire of the patient to avoid recurrent episodes of instability (including the necessity of reporting to the emergency room on a frequent basis to have the shoulder reduced), problems with recurrent pain, an inability to perform certain activities because of apprehension regarding the shoulder, and the desire to improve athletic performance with improved shoulder stability. Failure of a thorough trial of nonoperative treatment is also an indication for surgical treatment.

Indications for open stabilization over arthroscopic stabilization include (1) participation in a contact or collision sport, (2) male patients under the age of 20 with instability, (3) small to moderate bony defects of the humeral head or glenoid, (4) humeral avulsion of the glenohumeral ligaments, (5) failed arthroscopic repair, and (6) atraumatic instability. Essentially, patients with an Instability Severity Index Score of 6 or greater (in which arthroscopic methods have a reported failure rate of 70%)²¹ are candidates for open capsular repair. In our practice, such patients represent approximately 80% of the patients who fail conservative treatment and require surgical treatment for anterior instability.

CONTRAINDICATIONS

Contraindications to the open technique include voluntary instability and concomitant psychological disease. Large Hill-Sachs lesions or glenoid lesions may (in our opinion, rarely) require supplemental bone grafting to compensate for the defects. In our practice, such procedures are generally reserved for patients who have failed an attempt at open capsular repair—an uncommon situation. Because we have noted a slightly higher recurrence rate in patients with large Hill-Sachs lesions (11% vs 2% in all patients), in recent years we have been performing arthroscopic remplissage³⁰ in combination with open Bankart repair in patients with such lesions.

We prefer to utilize arthroscopic methods of stabilization in athletes whose primary focus is throwing and in other overhead athletes who cannot accept any restrictions in postoperative motion.
If an arthroscopic method is utilized in an overhead athlete, we strongly encourage the surgeon to have a frank discussion with the athlete and their family about the high risk of recurrent instability should the athlete return to contact sports. We subtly encourage the multisport athlete to prioritize the importance of their various athletic pursuits. If a contact sport is deemed the priority, we recommend an open repair. In such a case, we do not hesitate to delay operative intervention until the postseason if the athlete has infrequent episodes of instability and can continue to play at a level that they find acceptable. On the other hand, if an overhead sport is deemed to be the primary concern, we encourage early arthroscopic repair. Only in the unusual case that an open method is used in a throwing or overhead athlete (ie, after failed arthroscopic repair in an athlete who continues to prioritize an overhead sport), do we use the technique in which the subscapularis tendon is split rather than detached.

PREOPERATIVE PREPARATION

History

The diagnosis of an anterior shoulder dislocation is usually obvious. The patient typically gives a history of a traumatic injury in which the shoulder “popped out” and had to be reduced. Often, the arm is positioned in abduction and external rotation at the time of the episode. In some cases, however, dislocation can occur without a history of significant trauma. These latter patients are frequently noted to have generalized ligamentous laxity and multidirectional instability and are less likely to demonstrate a Bankart lesion. Such patients typically have enlargement of the rotator interval and loose capsular tissue.

The diagnosis of anterior subluxation can be more subtle. The chief complaint may be a sense of movement, pain, or clicking with certain activities. Pain, rather than instability, may be the predominant complaint. The pain commonly localizes in the bicipital groove are and to the infraspinatus fossa, possibility due to compensatory overload of the dynamic stabilizers of the shoulder.

Physical Examination

Apprehension tests are designed to induce anxiety and protective muscular contraction as the shoulder is brought into a position of instability. The anterior apprehension test is performed with the arm abducted and externally rotated. As the examiner progressively increases the degree of external rotation, the patient develops apprehension that the shoulder will “slip out.” This test is uniformly positive in patients with anterior instability.

During the relocation test, the examiner’s hand is placed over the anterior shoulder of the supine patient. A posteriorly directed force is applied with the hand to prevent anterior translation of the humeral head. The shoulder is then abducted and externally rotated as it is in the apprehension test. A positive result is obtained when this anterior pressure allows increased external rotation and diminishes associated pain and apprehension. The relocation test seems to be more reliable in overhead athletes and may not be positive in all cases of anterior instability.

The belly-press, lift-off, and bear hug tests should also be performed to confirm the integrity of the subscapularis tendon.

Imaging

Routine radiographic examination of the unstable shoulder includes an anteroposterior (AP) view (deviated 30°-45° from the sagittal plane in order to parallel the glenohumeral joint), a trans-scapular (Y) view, and an axillary view. West Point and Stryker Notch views are helpful in demonstrating bony lesions of the humeral head and glenoid.

Magnetic resonance imaging (MRI) is useful to determine if a Bankart lesion is present and also to assess patients for evidence of concomitant rotator cuff or superior labral pathology. The accuracy of MRI in determining labral pathology is, in our experience, increased with arthrography. Because of the possibility of concomitant rotator cuff injury, MRI should always be considered in older patients with instability—especially if strength and motion are slow to recover after a traumatic episode.

Computed tomography (CT) scans may be indicated if bony deficiency is suspected on plain films. However, the surgeon should be cautioned that CT tends to overestimate the size of larger glenoid lesions and that CT measurement of smaller lesions is not superior to arthroscopic measurement.

Timing of Open Bankart Repair

As mentioned above, we do not hesitate to delay open surgical treatment of anterior instability until an athlete completes their competitive season. While there is increasing evidence that the results of arthroscopic stabilization are less satisfactory when surgery is delayed or after multiple recurrences,²⁹^,³¹ delaying open repair has had no such negative impact on recurrence rates in our experience.

TECHNIQUE (

VIDEO 33-1)

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VIDEO 33-1

The Bankart procedure involves repair of the anterior capsule and labrum to the glenoid. In most cases, the capsular ligaments are stretched as well as detached, and our technique is also designed to remove any abnormal capsular laxity. Our technique has developed over the years based on the teachings of Russell F. Warren, MD, to whom we are deeply indebted.

Anesthesia

The procedure is performed after preoperative placement of both an interscalene block and an interscalene catheter for postoperative analgesia. In most cases, the block is supplemented with general laryngeal mask airway anesthesia. In properly selected patients, the procedure may be performed using regional anesthesia alone.

The skin incision is marked with indelible ink in the preoperative holding area. The patient is asked to internally rotate the shoulder, and the skin crease in the anterior axilla is identified. A line is then drawn on the skin in extending from the anterior axillary crease to a point inferior and 1 to 2 cm lateral to the coracoid along Langer lines (Figure 33-1).

FIGURE 33-1 Incision along the anterior axillary crease.

Arthroscopic Examination

We routinely perform a complete arthroscopic examination before proceeding with the open procedure. The patient is placed in the beach-chair position with the head elevated to 60°. Before elevation of the head, an arm board is attached to the operative side of the table and folded sheets are taped to the arm board (Figure 33-2). The arm board is then placed against the side of the table to provide arthroscopic access to the shoulder until conversion to the open procedure. A mechanical arm holder is used to control shoulder position during arthroscopy. The shoulder is examined through standard anterior and posterior arthroscopic portals. Supplementary portals are created if indicated based on the findings of labral or rotator cuff pathology. Any loose bodies are removed during arthroscopy. When superior or (less commonly) posterior labral tears accompany anterior instability, they are repaired arthroscopically since these parts of the labrum are inaccessible with an open anterior approach. Similarly, supraspinatus or infraspinatus pathology is addressed with arthroscopic treatment prior to the open procedure. When sizable Hill-Sachs lesions are noted in patients at high risk for recurrent instability, we now commonly perform arthroscopic “remplissage” to cover the defect prior to the open repair.³⁰ The arthroscopic examination is also helpful in determining the specific anterior pathology prior to the open repair.

FIGURE 33-2 Folded sheets placed on an arm board under the elbow aid in maintaining reduction during the repair.

Conversion to Open Procedure and Positioning of Surgeon and Assistants

After completion of the arthroscopic examination and treatment, the posterior and any accessory portals are closed. The arm is detached from the mechanical arm holder. The head of the operating table is lowered to 15° of elevation, and the previously placed arm board is rotated away from the table so that the upper extremity can be abducted 45° on an arm board. The folded sheets, which had been taped to the arm board, are placed beneath the elbow. The sheets help maintain the arm in the coronal plane of the thorax and minimize extension of the shoulder, facilitating reduction of the glenohumeral joint during the capsular repair.

Two assistants are utilized. The surgeon initially stands in the axilla. After the development of the deltopectoral interval and placement of self-retaining retractors, the surgeon moves to the lateral aspect of the shoulder and the first assistant assumes position in the axilla. The first assistant’s primary responsibilities are to control arm position and to keep the humeral head reduced during the capsular repair. The first assistant also holds the humeral head retractor when it is in position. The second assistant stands on the contralateral side of the table and holds the medial (glenoid) retractors.

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