Biomechanical evaluation of subscapularis peel repairs augmented with the long head of the biceps tendon for anatomic total shoulder arthroplasty

Background: Subscapularis failure is a troublesome complication following anatomic total shoulder arthroplasty (aTSA). Commonly discarded during aTSA, the long head of the biceps tendon (LHBT) may offer an efficient and cheap autograft for the augmentation of the subscapularis repair during aTSA. The purpose of this study was to biomechanically compare a standard subscapularis peel repair to 2 methods of subscapularis peel repair augmented with LHBT. Methods: 18 human cadaveric shoulders (61 +/- 9 years of age) were used in this study. Shoulders were randomly assigned to biome-chanically compare subscapularis peel repair with (1) traditional single-row repair, (2) single row with horizontal LHBT augmentation, or (3) single row with V-shaped LHBT augmentation. Shoulders underwent biomechanical testing on a servohydraulic testing system to compare cyclic displacement, load to failure, and stiffness. Results: There were no significant differences in the cyclic displacement between the 3 techniques in the superior, middle, or inferior portion of the subscapularis repair (P > .05). The horizontal (436.7 +/- 113.3 N; P = .011) and V-shape (563.3 +/- 101.0 N; P < .001) repair demonstrated significantly greater load to failure compared with traditional repair (344.4 +/- 82.4 N). The V-shape repair had significantly greater load to failure compared to the horizontal repair (P < .001). The horizontal (61.6 +/- 8.4 N/mm; P < .001) and the V-shape (62.8 +/- 6.1; P < .001) repairs demonstrated significantly greater stiffness compared to the traditional repair (47.6 +/- 6.2 N). There was no significant difference in the stiffness of the horizontal and V-shape repairs (P = .770). Conclusions: Subscapularis peel repair augmentation with LHBT autograft following aTSA confers greater time zero load to failure and stiffness when compared to a standard subscapularis peel repair. Level of evidence: Basic Science Study; Biomechanics (c) 2022 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.