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Arthroscopic Bankart repair: indications and technique
Technical advances, plus an end to worrisome recurrence rates, make arthroscopic stabilization the procedure of choice.
Recent technical advances combined with improvements in implant choice and suture material have turned arthroscopic stabilization for anterior shoulder dislocation into the procedure of choice. Despite initial studies revealing worrisome recurrence rates, current arthroscopic techniques are associated with failure rates of 5% to 10%, comparable to open procedures.
The advantages of an arthroscopic approach include less surgical morbidity, less postoperative pain, the reduced cost of an outpatient setting, improved cosmesis and an easier, if not shorter, rehabilitation. Younger patients and even contact athletes are suitable candidates for arthroscopic stabilization procedures. However, there are circumstances in which an open stabilization procedure might be preferable to the arthroscopic approach, namely those with significant glenoid and/or humeral head bone loss and those with compromised inferior glenohumeral ligament quality.
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Images: Ryu RKN |
1. The lateral decubitus position is preferred. The table is rotated 90° such that the surgeon can move from back to front around the patient’s upper torso without impediment. The table is tilted 10° to 15° to orient the glenoid horizontal to the floor. The arm is placed in a dual traction sleeve with longitudinal balanced suspension of 8 to 10 pounds complemented by axial traction with similar weight. This facilitates glenohumeral joint distraction. Examination under anesthesia confirms the diagnosis.
2. Dual anterior portals are established with the anterior-inferior portal (AIP) directly superior to the intra- articular slip of the subscapularis, occupying the lowest portion of the rotator interval while the anterior-superior portal (ASP) is placed at the superior border of the interval, directly behind the biceps tendon (Figures 1 and 2). A posterior portal is created slightly lateral to and above the glenoid rim. This permits the posterior portal to become a working portal without interference from the glenoid rim (Figure 3). After a thorough diagnostic evaluation from the posterior portal, viewing from the ASP now affords a direct view of the anterior glenoid and the glenohumeral ligaments (Figure 4).
3. The Bankart lesion is identified (Figure 5), and all other pathology acknowledged including associated capsular tears (Figure 6), humeral avulsions of the glenohumeral ligament (Figure 7), bony defects, rotator cuff and biceps injuries. Although considered the essential lesion, a Bankart lesion alone is not sufficient to cause recurrent instability. Some element of capsular deformation accompanies the primary pathology and must be addressed in addition to the side-to-side closure of the Bankart defect.
4. The Bankart lesion must be thoroughly elevated from the glenoid neck such that the subscapularis is clearly visible through the defect (Figure 8). This step is critical to the sucess of the procedure. If an anterior ligamentous periosteal sleeve avulsion is noted, the dissection can be tedious due to inferior and medial scarring (Figures 9 and 10). Avoid inadvertent thinning of the glenohumeral ligament. A grasping tool is used to evaluate whether the tissue can then be shifted in an inferior to superior direction to correct the ligament attenuation (Figure 11).
5. Once the ligament has been completely liberated, the glenoid neck is gently prepared with a shaver or curette. Use of a motorized burr on the medial neck of the glenoid is rarely needed. A burr can be used to debride a small bony Bankart lesion by placing the burr on reverse. The bony fragment can be removed without harming the ligament.
6. Through the AIP, instrumentation for anchor placement is positioned at the lowest anchor site, eg, 7-o’clock in a left shoulder. The drill hole for the anchor must be placed on the glenoid face, 2 mm to 3 mm onto the articular surface (Figure 12). This step is essential in recreating the labral “bumper,” and re-establishing the concavity-compression phenomenon. Avoid placing anchors on the glenoid neck as it increases recurrent instability risk (Figure 13).
7. Once the double-loaded suture anchor is inserted, one set of sutures is placed outside of the working posterior cannula using a switching stick technique. The remaining suture pair is separated with one strand exiting the posterior cannula. A suture hook loaded with No.1 PDS is used to penetrate the inferior glenohumeral ligament 1 cm to 2 cm inferior and lateral to the anchor (Figure 14). This permits adequate tissue shifting as well as a lateral to medial closure.
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8. The No. 1 PDS suture is retrieved through the posterior cannula and serves as a suture shuttling device. The separated suture strand from the anchor is loaded into a simple loop created in the No. 1 PDS. The suture limb is then retrograded through the glenohumeral ligament, and pulled through the AIP (Figure 15). The suture strands should be separated during this process to prevent tangling and to facilitate subsequent knot-tying.
9. The suture limb passing through the labrum must be designated as the post when tying knots. Whether the knot slides or is composed of alternating half-hitches, placing knots down the proper post will “push” the labrum up and onto the glenoid face. This recreates the labral height (Figures 16, 17 and 18), thereby re-establishing glenoid depth and enhancing the concavity-compression phenomenon.
10. After a minimum of three double-loaded anchors have been inserted, and the six high-strength sutures retrograded through the detached labrum, stability testing is appropriate. Forward flexion and external rotation of 90° and 30° respectively should be achieved without undue tension on the repair. The humeral head should be well centered in the glenoid when seen from the ASP (Figure 19). The ability to subluxate or dislocate the shoulder should now be corrected. Additional capsular tucks can also be placed at this time if the capsule is not properly tensioned.
11. In a small percentage of cases, associated ligamentous laxity may need to be addressed in addition to the Bankart lesion. Closure of the rotator interval can function as an internal splint while the labral lesion heals. A simple technique for interval closure consists of placing two No. 1 PDS sutures through the superior rotator interval using the AIP cannula, which has been carefully withdrawn to the outer capsular margin. An angled retrieving instrument can be passed through the same cannula, piercing the middle glenohumeral ligament to capture the PDS sutures (Figure 20).
The sutures are then tied through the AIP cannula, closing the interval. Often the knot-tying is not visible as the cannula is extra-capsular. A blind knot-cutter establishes the proper suture tail length. The use of absorbable suture may diminish the concern regarding potential motion loss with interval closure.
The postoperative regimen consists of a shoulder immobilizer in neutral rotation for a minimum of 4 weeks. The neutral position may improve post-op labral positioning as the subscapularis, under tension in the neutral position, coapts the labrum up and onto the glenoid surface. At 3 weeks to 4 weeks postop, dangling exercises are initiated, and 1 week to 2 weeks later, active-assisted motion followed by active range of motion is initiated. The goal is to recover 90% of motion at 12 weeks. For the elite level thrower, establishing full range of motion occurs at 8 weeks to 9 weeks. Combined abduction and external rotation exercises are started at 12 weeks, and a return to unrestricted activities, including contact or collision sports, is permitted at 5 months postop.
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For more information:
- Ryu RKN. Arthroscopic approach to traumatic shoulder instability. Arthroscopy (Dec. Suppl 1), 2003:94-101.
- Ryu RKN, Open versus arthroscopic stabilization for traumatic anterior shoulder instability. Sports Med Arthrosc Rev. 2004:90-98.
- Mazzoca AD, Brown FM, Carreira DS, et al. Arthroscopic Shoulder Stabilization for Contact and Collision Athletes. Am J Sports Med. 2005:52-60.
- Speer K, Deng X, Borrero S, et al. Biomechanical evaluation of a simulated bankart lesion. J Bone Joint Surg. [Am]. 1994;76A:1819-1826.
- Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart Repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy. 2000:677-694.