Using Interconnected Knotless Anchor for Suprapectoral Biceps Tenodesis Could Offer Improved Biomechanical Properties in a Cadaveric Model

Abstract

To compare the biomechanical characteristics of the interconnected knotless anchor (IKA) fixation with the double knotless anchor (DKA) and interference screw (IS) fixation in the suprapectoral biceps tenodesis. In total, 24 fresh-frozen human cadaveric shoulders (mean age, 67.3 ± 6 years) were used for the study. All the specimens were randomly divided into 3 experimental biceps tenodesis groups (n= 8): IKA, DKA, and IS. After tenodesis, each specimen was preloaded at 5 N for 2 minutes, followed by a cyclic loading test from 5 to 70 N for 500 load cycles. Finally, a destructive axial load to failure test (1 mm/s) was performed. All the values, including ultimate failure load, stiffness, cyclic displacement, and mode of failure were evaluated. The IKA provided the highest construct stiffness (38.9 ± 7.7 N/mm) and ultimate failure load (288.3 ± 47.6 N), the results for which were statistically better than the corresponding results in the IS and DKA groups. In terms of cyclic displacement, there were no statistical differences among the 3 fixation constructs. The most common failure mode was biceps tendon tearing in IS group (7/8) and IKA group (8/8). In the contrast, suture slippage accounted for the most common failure mode in DKA. In suprapectoral bicep tenodesis, IKA fixation appears to offer improved construct stiffness and ultimate failure load while maintaining comparable suture slippage as compared with IS fixation or DKA fixation in the current biomechanical study. The IKA fixation compares favorably with other techniques and could be an alternative clinical option for suprapectoral biceps tenodesis.