Case 12

Recurrent Anterior Shoulder Instability. The patient’s history of recurrent dislocations requiring reduction makes the diagnosis straightforward. However, determining the direction of the instability is of great importance. A careful history should be obtained regarding the activities that result in shoulder dislocation and the position of the arm at the time of dislocation. Often, the patient will specifically relate the position of the arm that leads to dislocation of the shoulder. Although anterior shoulder instability is much more common than posterior instability, recurrent posterior shoulder dislocations do occur. A careful physical examination will also help to determine the direction of instability. Careful translation testing both anteriorly and posteriorly allows the physician an opportunity to assess the restraining function of the glenohumeral ligaments. Comparison with the opposite extremity is of paramount importance, as great variability exists in normal shoulder translations. However, some variability may exist between the shoulders of an individual without preceding injury or symptoms. Finally, provocative maneuvers such as the apprehension test and relocation test help in determining the direction of instability. Positioning the patient’s arm in maximum abduction and external rotation may reproduce a feeling of impending instability. Posterior translation of the humeral head during this test that alleviates the sense of apprehension is considered a positive relocation test. These are both excellent tests to evaluate for anterior instability if true apprehension is elicited during the exam. However, merely eliciting pain in the position of abduction and external rotation is much less sensitive for anterior shoulder instability and often results from rotator cuff pathology.

Zone-specific load and shift maneuvers can be valuable in helping to rule out a multidirectional instability pattern and may influence the surgeon’s choice of operative technique. In zone-specific testing the examiner’s thumb is used as a fulcrum for loading the anterior stabilizing structures. To examine the right shoulder, the surgeon stands behind the patient. The surgeon’s left hand is used to stabilize the scapula, the left thumb is placed behind the humeral head, and the right hand, while the holding the patient’s flexed elbow, is used to load the joint (Fig. 12–1). Using this method the anterior-superior, direct anterior, and anterior-inferior components of stability can be individually evaluated.

Surgical Management

After adequate induction of general or interscalene regional anesthesia, the patient is placed in the standard lateral decubitus position rolled posteriorly 30 degrees. Alternately, the patient can be placed in the beach chair position. Stability testing is then performed to confirm the degree and direction of instability. With one hand, the examiner applies an axial load at the elbow to center the humeral head on the glenoid. The other hand is then used to translate the humeral head anteriorly and posteriorly. Grading is recorded as 1+ when increased translation is present compared with the opposite extremity but is insufficient to cause humeral head subluxation over the glenoid rim. An instability grading of 2+ is assigned when the examiner could subluxate the humeral head over the glenoid, but the head spontaneously reduces to its anatomic position when the force is removed. A 3+ grading signifies the ability of the examiner to lock the humeral head over the glenoid rim. Following an exam under anesthesia, a standard sterile prep and drape is then performed and the arm suspended with 10 to 15 pounds of traction in 45 degrees of abduction and 20 to 30 degrees of forward flexion, if the lateral decubitus position is employed.

A posterior portal is initially established in the interval between the infraspinatus and teres minor tendons and a diagnostic arthroscopic examination performed. The presence of a Bankart lesion is confirmed and other pathology noted. A second portal is established anteriorly utilizing an outside-in technique to ensure proper positioning of this anterior portal. The portal should be established so that the surgeon will have access at a proper angle in three planes to the glenoid rim for anchor placement at the 1, 3, and 5 o’clock positions, as well as access to the anterior and inferior capsulolabral ligamentous complex for suture placement at the 2, 4, and 6 o’clock positions (Fig. 12–2). Localization with a spinal needle prior to placement of the cannula ensures adequate placement. A cannula for instrumentation is then inserted into the joint at the upper edge of the subscapularis tendon running through the lower aspect of the rotator interval, just lateral to or above the middle glenohumeral ligament.

The labral edge is debrided of degenerative tissue, and the capsulolabral ligamentous complex is completely released from the glenoid neck down to the 6 o’clock position (Fig. 12–3). A high-speed burr is then used to abrade the anterior and inferior glenoid neck down to the 6 o’clock position. The debridement and abrasion are necessary to allow an adequate vertical shift of the damaged capsulolabral structures and adequate healing of the repair once the reconstruction is completed. Often the avulsed labrum has healed or partially healed medially on the glenoid neck. Extensive freeing of the labrum in this area must be performed to allow adequate mobilization. This may be accomplished with rasps, shavers, burrs, or knives.

A nonmodified Caspari suture punch (Linvatec) is then inserted through the anterior portal. A 48-inch doubled 2.0 Prolene suture (Ethicon) is loaded with the two free ends passed into the suture punch and the loop portion remaining proximally (Fig. 12–4A). The suture punch is inserted into the joint and used to pass this double suture through the inferior glenohumeral ligament, lateral to its labral attachment, at approximately the 6 o’clock position (Fig. 12–4A,B). The suture punch is withdrawn, pulling both the free ends and the loop end outside of the same cannula. A no. 2 Ticron suture is then placed in the loop. By pulling on the two free ends the suture is passed through the inferior glenohumeral ligament (Fig. 12–5).

The drilling guide is placed into the joint through the suture punch cannula. The first or inferior hole is drilled at the edge of the glenoid articular surface at approximately the 5 o’clock position. The guide tip is wedged onto the glenoid neck-face junction and fulcrumed downward against the soft tissues so that the drill is perpendicular to the vertical axis of the glenoid (Fig. 12–6). The pilot hole is drilled, maintaining adequate visualization from the posterior portal. While visualizing from the posterior portal, it is critical that the drill hole is placed with at least half the diameter of the hole into the edge of the articular surface of the glenoid, thereby assuring optimal anchor placement. The anchor is loaded on the inserter and held in position with an absorbable 2-0 Vicryl suture. The inner limb of the Ticron suture is threaded through the anchor and the anchor inserted into the previously drilled pilot hole (Fig. 12–7). The anchor is carefully tested by pulling on the 2-0 Vicryl suture, which is removed after adequate holding power is confirmed.

The suture punch is reinserted into the joint and a second doubled Prolene placed through the inferior glenohumeral ligament approximately 5 mm more superiorly than the initial suture (5:30 to 5:45 clock position). This Prolene is used to pull the inner limb of the Ticron suture through the inferior glenohumeral ligament, creating a horizontal mattress suture and allowing capsular plication (Fig. 12–8A,B). An arthroscopic knot tying device is used to tie the two ends of the Ticron suture, repairing the inferior glenohumeral ligament to the glenoid, while advancing it superiorly. This will eliminate inferior capsular redundancy (Fig. 12–8C,D).

Each step is then repeated, inserting a second and third anchor in similar fashion (Fig. 12–9). The sutures are generally placed at the 6, 4, and 2 o’clock positions into the capsule, with the anchors inserted at the 5, 3, and 1 o’clock positions on the glenoid rim (Fig. 12–2). Placing the sutures inferior to the anchor allows a superior shift of the capsule, eliminating inferior redundancy and correcting any plastic deformity that may exist in the capsular or ligamentous tissues. Mattressing the suture allows plication of the capsule and helps eliminate redundancy.

Anchor-First Technique

As an alternative to the above techniques, the Ticron sutures of the 3 o’clock and 1 o’clock anchors can be pulled through the labrum with a retrograde suture retriever (Innovasive Devices) (Fig. 12–10). This is accomplished by placing the 15-, 30-, 45-, or 60-degree suture retriever through the anterior cannula and then passing it through the labrum at the same location described for the Caspari punch. This will reproduce the horizontal mattress suture and capsular plication required for the repair. This device simplifies the suture passing, but is unable to efficiently reach the 6 o’clock position on the labrum required for the inferior suture.

Knot Tying

Harryman and colleagues (1992) have shown that the most secure knot configurations are achieved by reversing half-hitch throws while alternating the post (Fig. 12–11A). Using this technique, five throws are recommended. A modified slipknot, called the Roeder knot, can also be used. The authors prefer a modification of the Roeder knot; it is accomplished by throwing the first half of a square knot leaving one end long and one end short (Fig. 12–11B). The long end is then passed around both limbs of the suture three times, then once around the short limb. The long limb of the suture is then passed through the loop adjacent to the half square knot (Fig. 12–11C). The knot is then compressed by spreading the distal limbs while holding the short limb as a post (Fig. 12–11D). The knot is advanced by pulling on the short limb. It is imperative that the long limb is not pulled until the knot is snug against the soft tissues and has approximated the Bankart lesion, because this will lock the knot. The knot is then secured by at least one single half hitch using the short limb as a post.

Once the repair is completed, the shoulder is tested for adequate stability while visualizing the glenohumeral articulation from both the anterior and posterior portals. Specific attention is directed toward any laxity of the posterior-inferior gleno humeral ligament and rotator interval. In most cases in which the above technique has been performed correctly, there has been no laxity posteriorly.

The importance of the rotator interval in shoulder instability has been established in cadaveric and clinical reports. Arthroscopic plication of the rotator interval is sometimes carried out after arthroscopic Bankart repair to supplement the labroligamentous reapproximation. The rotator interval may be plicated by one of two methods. Maintaining the arthroscope in the posterior portal, a transporter or suture retrieval device is inserted through the capsule adjacent to the subscapularis tendon and through the middle glenohumeral ligament. Occasionally a small portion of the subscapularis may be included in this repair, but it is important to include the capsule anterior to the subscapularis as well as a portion of the middle glenohumeral ligament. A spinal needle is then placed through the skin in the area of the anterior-superior portal, adjacent to the anterior-lateral corner of the acromion, and through the capsule adjacent to the anterior margin of the supraspinatus tendon. A no. 1 Pro lene suture is then passed through the spinal needle and retrieved out the anterior portal, using the transporter device (Fig. 12–12). This suture will close or plicate the more lateral portion of the rotator interval. The transporter can then be placed back down the anterior cannula and through the capsule medial and superior to the first stitch, allowing passage of a second or third stitch as needed.

Related posts:

11. Anterior Instability: Open Repair Technique 9. Lateral Third Clavicle Fractures 47. Triceps Rupture 56. Osteochondritis 39. Valgus Instability 42. Essex-Lopresti Lesion

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