Purpose: Tuberosity Repair in Reverse Shoulder Arthroplasty (RSA) for proximal humerus fractures with deficient Rotator Cuff (RC) is a challenging task. With the advent of newer generation high strength hybrid suture materials, the entire burden of the repair lies on the Knot Security. We hereby want to study the biomechanical strength and tensile load to failure (LTF) of the most commonly performed the surgical knot and the nice knot with different suture materials available in the market. Methodology: This study included the use of second and third generation non-absorbable hybrid polyethylene core sutures. The knot tying methods that were tested included the Surgical knot and the Nice Knot. The instrument, used to measure the tensile load to failure of each of these knots using different sutures, was Autograph-Shimadzu. 3 mm slippage or opening of the suture loop was taken as knot failure. Results: Knot security varied based on the method used to tie it. Average LTF for surgical knot was 0.316 KN against 0.582 KN for Nice Knot. Nice Knot was most secure with Striated Ultrabraid (0.968 KN LTF). Conclusion: Knot-suture combinations affect strength of fixation. In our study, statistically significant difference was found between the knot security by Surgical and Nice techniques (p value<0.044, t-value 2.130). Nice knot had higher load to failure and hence should be favored over surgeon’s knot, when using newer generation suture materials, for a robust tuberosity repair.
