A “Comma Sign”–Directed Subscapularis Repair in Anterosuperior Rotator Cuff Tears Yields Biomechanical Advantages in a Cadaveric Model

Background: Additional stabilization of the “comma sign” in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair. Purpose: This in vitro investigation aimed to investigate the influence of a comma sign–directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair. Study Design: Controlled laboratory study. Methods: A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups. Results: The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred ( P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared ( P = .596). Conclusion: The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading. Clinical Relevance: The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.

The Use of the Comma Sign and Tissue for Recognition, Reduction, and Stability During Arthroscopic Repair of Combined Anterosuperior Cuff Tears

Background: The comma sign is a useful marker for combined retracted supraspinatus and subscapularis tears. It was first described by the group of Burkhart as a “composite ligamentous structure” of the rotator interval attached to the retracted subscapularis. However, Neyton and coworkers suggested that the ruptured superior part of subscapularis is pulled upward by supraspinatus retraction. This video illustrates the value of “comma” recognition for reduction and repair stability. We feel that the comma tissue can be a composition of rotator interval ligaments with or without superior subscapularis contribution depending on an associated cleavage tear. Indications: Patients with retracted anterosuperior tears, unless muscle quality is poor (Goutallier classification ≥3). Understanding of the comma tissue is difficult but of crucial importance to assess complex anterosuperior cuff tears for reduction and repair with stability by maintaining and integrating this comma link into the repair construct. Technique Description: Arthroscopic setup includes beach chair position, armholder, cerebral saturation monitoring (target mean arterial blood pressure of about 70 mm Hg). Previously described circumferential portals were used for a repair with a double row construct (4 medial anchors: 2.5 for subscapularis; 1.5 for supraspinatus) and 2 lateral anchors. The superior boarder of subscapularis as well as the retracted capsular layer of supraspinatus was reduced and fixed using a lasso loop technique. Key stages are (1) tendon manipulation with 2 traction sutures; (2) tendon release; (3) comma reduction; (4) footprint preparation (burr, microfracture); (5) retrograde suture passing; (6) knot tying, knotless lateral row; and (7) a close surgeon to physiotherapist rehabilitation link (6 weeks passive to 90°, no resistance training for 3-6 months). Results: Senior author’s (S.B.) series: 32 anterosuperior tears over 4 years (mean age: 62 years, 48-73 years), minimum follow-up 1 year showed good results (mean SSV: 85% [preop. 35%], range: 40%-95%; mean Constant: 82 [preop. 30], range: 40-90). One major complication (cutibacterium infection; brick layer; workers compensation; invalidity demand; Constant/Subjective Shoulder Value both 40) and minor temporary stiffness at 3 months (8 patients; 22%). Conclusion: Adequate reduction and comma integration into a solid repair construct, as well as responsible rehabilitation surveillance, deliver successful results after technically intricate anterosuperior repairs.