Chapter 3 Instability

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CHAPTER 3 | Instability

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.

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

The Cowboy’s Conundrum: Recurrent Anterior Instability with Off-track Hill- Sachs Lesion The Surgeon’s Solution: Arthroscopic Bankart Repair plus Remplissage with Knotted Double-pulleyTechnique 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/exter- nal 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).

■ Mobilization of the capsulolabral complex must pro- ceed 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 anteroinfe- rior suture anchors through a standard anterior por- tal. 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 insta- bility (in addition to his ALPSA lesion) and that is an off-track Hill-Sachs lesion. A Hill-Sachs lesion is off- track 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 para- digm, this instability can be repaired arthroscopi- cally. However, since the Hill-Sachs lesion is an off-track lesion, we must perform an arthroscopic remplissage in addition to the arthroscopic Bankart repair.

Video 3-9