Illustrated Tips & Tricks CH16

116  Chapter 16 Arthroscopic Subscapularis Repair

nn The pump is run at an adequate pressure (minimum 60 mm Hg). nn Fluid extravasation from portals is stopped with cannulas or the Dutch boy technique (manual pressure by assistant) to minimize fluctuations in pressure and turbulence. • Recognition of the “comma sign” is critical when a retracted subscapularis tear is present. 4 nn The comma tissue is the lateral part of the rotator interval capsule and contains the coracohumeral and superior glenohumeral ligaments. nn The comma tissue connects the superolateral subscapularis tendon with the supraspinatus tendon. • In primary, retracted subscapularis tears, the upper tendon border usually lies at the middle of the glenoid. ll Working in the subcoracoid space is essential in treating subscapularis tears. • Work in this area is always started by opening the rotator interval medial to the comma with a shaver or cautery from an ASL portal while viewing with a 30-degree arthroscope from a posterior portal (Fig. 16-6A).

Figure 16-6 || Working in the subcoracoid space (left shoulder) requires repositioning of instruments posterior (A and B) and anterior (C) to the comma tissue ( black comma symbol ). Work with a 30-degree scope (A and B) until the interval has been opened and landmarks defined. A 70-degree scope improves the view (C) for working anterior to the tendon. C, coracoid; CT, conjoint tendon; H, humeral head; SS, supraspinatus tendon; SSc, subscapularis tendon.

• Once the anatomic landmarks have been identified, switching to a 70-degree scope allows an excellent view of the entire subcoracoid space (Figs. 16-6C and 16-7B) and lesser tuberosity foot- print (Fig. 16-7F). • The comma tissue is preserved (Figs. 16-6 and 16-7) because this tissue: nn Acts as a “rip stop” for sutures of the upper tendon nn Aids in reduction of the supraspinatus when a retracted anterosuperior tear exists • As needed, instruments are used either anterior (Fig. 16-6A and B) or posterior (Fig. 16-6C) to the comma to expose the coracoid, conjoint tendon, subscapularis tendon, and lesser tuberosity by removing pathologic fibrofatty and bursal tissue. ll All subscapularis tendon tears where there has been fiber failure from the footprint (Fig. 16-7F) are repaired. Abrasive wear of the tendon (Fig. 16-7E) or linear, longitudinal tearing without failure at the tendon insertion can occasionally be treated by subcoracoid decompression (Fig. 16-7) alone. • Subcoracoid stenosis (coracohumeral distance <6 mm) (Fig. 16-7B) is treated by removing any coracoid tip osteophyte with a burr (Fig. 16-7C). • The end point of this step occurs when the posterior coracoid is coplanar with the conjoint tendon and there exists 7-10 mm of space between the coracoid and the subscapularis tendon (Fig. 16-7D). ll Lesser tuberosity bone bed preparation is critical when repairing the subscapularis. • All soft tissue remnants are removed with electrocautery (Fig. 16-8A). • The “charcoal” bone is removed with a burr on reverse or a ring curette (Fig. 16-8B) to expose healthy bone to maximize the chances of healing of the repair. Repair Techniques